The Ultimate Luggage Set Buying Guide: Sizes, Materials, and Features (2025)

Sam Beckstein
Sam Beckstein
The Ultimate Luggage Set Buying Guide: Sizes, Materials, and Features (2025)

Planning your next trip? This comprehensive luggage set buying guide is your ultimate resource for choosing the perfect travel companion. We delve into everything you need to know, from understanding different luggage sizes and durable materials to exploring must-have features that enhance your travel experience. In this guide, updated for 2025, discover the best luggage sets available, tailored to fit every travel style and budget, ensuring you travel with ease and sophistication. Whether you're planning a weekend getaway or a long-haul adventure, we’ll help you navigate the world of luggage, considering everything from hardside vs. softside to the best carry-on luggage. Get ready to upgrade your travel game with this essential guide.

Our top picks

The Best Luggage Set for Budget Travelers: Amazon Basics 4-Piece Luggage Set, $71.00
The Most Durable Luggage Set for Frequent Flyers: Airconic Luggage by American Tourister, $175.00
The Best Stylish and Functional Luggage Set: Travelers Club Chicago 20" Carry-On Spinner Luggage, $121.18
The Best Luggage Set with TSA-Approved Locks: Pivot 3 Piece Set by Samsonite, $99.99

Decoding Luggage Sizes: Carry-On to Checked Bags

Learn the differences between luggage sizes to perfectly match your trip length and needs.

Maxlite 5 Carry-On/Check-In Set

Maxlite 5 Carry-On/Check-In Set

$311.92

Travelpro’s Maxlite 5 Carry-On/Check-In Set balances light weight and durability well, earning a 7/10 in our hands-on tests. We found the DuraGuard® coated polyester resists water and stains, the 360-degree spinner wheels make rolling effortless, and the low overall weight is a real benefit at the gate. On the downside our experience shows some users encounter a persistent chemical odor in the lining and the expandable capacity is limited, plus there’s no integrated TSA lock, so bring a small padlock if security is a concern.

The Good

Lightweight design makes it easy to handle and carry.

Smooth 360-degree spinner wheels for effortless maneuvering.

Durable polyester fabric with water and stain-resistant DuraGuard® coating.

The Bad

Some users report a strong chemical odor in the lining that persists despite airing out.

The expandable feature provides limited additional space, which may not meet expectations.

Lacks integrated TSA-approved locks, requiring users to provide their own for added security.

Material: Softside / Wheel Type: Spinner / Expandable: true / Security Features:

Coolife 3 Piece Luggage Set

Coolife 3 Piece Luggage Set

$199.99

The Coolife 3 Piece Luggage Set is pleasingly lightweight with smooth-rolling spinners and built-in TSA locks we appreciated during our review, making it a strong option for easy airport navigation. That said, our experience shows the ABS shell is prone to scratches and scuffs after regular use, and some users reported issues with lock quality and warranty support which lowers long-term confidence. Given its $199.99 price and a 6/10 score, it’s a practical, budget-friendly choice if you don’t need rugged, heavy-duty durability.

The Good

Lightweight and easy to handle.

Smooth rolling wheels.

Built-in TSA lock.

The Bad

Scratches and scuffs on the ABS shell after regular use.

Some issues with TSA lock quality.

Coolife customer service and warranty replacement can be an issue.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock

Choosing the Right Luggage Materials

Explore durable materials like polycarbonate, aluminum, and fabric for your luggage sets.

Airconic Luggage by American Tourister

Airconic Luggage by American Tourister

$175.00

American Tourister’s Airconic offers convenient security and organization for casual travelers, and during our review we appreciated the built-in TSA lock and multiple packing compartments. It scored a 6/10 overall — we found the lightweight hardside shell easy to maneuver and the interior pockets practical, but zipper failures and reports of fabric holes after minimal use raise red flags for reliability. For short trips where security and organization matter this is attractive and affordable, but frequent flyers should be cautious about long-term durability.

The Good

Lightweight design makes it easy to handle and maneuver during travel.

The suitcase features a built-in TSA-approved lock for added security.

The luggage offers multiple compartments and pockets for efficient packing.

The Bad

Some users report zipper failures after minimal use, leading to potential security issues.

Durability concerns have been raised, with instances of the suitcase developing holes after the first trip.

Some customers have experienced issues with the wheels, including wear and tear after limited use.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock

Freeform Luggage Set by Samsonite

Freeform Luggage Set by Samsonite

$174.99

Samsonite’s Freeform Luggage Set is one of the better mid-priced hard-shell options we tested, earning an 8/10 for its blend of strength and smooth handling. In our testing the expandable design and double-spinner wheels made packing and rolling effortless, and the TSA lock adds needed security; the set’s lightweight build is another real plus for avoiding overweight fees. Be aware our experience shows the glossy finishes scratch more easily and the 21" carry-on can be tight when expanded, and it lacks external pockets for quick-access items.

The Good

Lightweight yet durable construction.

Smooth-rolling double spinner wheels.

Expandable design for extra packing space.

The Bad

May scratch easily, especially on glossy finishes.

21" carry-on might be tight for some airlines when expanded.

No external pockets for quick access items.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock

The Good

The luggage set features 360-degree spinner wheels for easy maneuverability.

The set includes multiple pockets for organized packing.

The luggage is lightweight, aiding in adhering to airline weight restrictions.

The Bad

Some users reported issues with zippers failing when overpacked.

The fabric may pick up dirt easily, especially in lighter colors.

The underseat bag has only two wheels, making it less maneuverable compared to four-wheel designs.

Material: Softside / Wheel Type: Spinner / Expandable: true / Security Features:

DELSEY PARIS Chatelet Air 2.0 Luggage Set

DELSEY PARIS Chatelet Air 2.0 Luggage Set

$218.80

Delsey Paris’ Chatelet Air 2.0 is one of our top-rated choices, earning a 9/10 because in our testing the recessed TSA combination lock, SECURITECH zip, and dual-density double-spinner wheels combined for secure, silky rolling travel. We also appreciated the thoughtful interior with a laundry bag, shoe bag, and mesh pockets that kept outfits organized during longer trips, though our review notes lighter colors can show wear and the USB port needs your own charger. If you want premium security and refined handling without compromise, this set stands out.

The Good

The luggage features dual-density, double-spinner wheels for smooth 360-degree maneuverability.

The interior includes a laundry bag, shoe bag, and mesh zippered pockets for organized packing.

The luggage is equipped with a recessed 3-dial TSA-approved combination lock and SECURITECH zip for enhanced security.

The Bad

The carry-on size might be slightly larger for some smaller planes' overhead compartments.

The luggage can show wear quickly, especially in lighter colors.

The USB port requires an additional charger, which is not included.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock,Zipper Lock

Samsonite Winfield 2 Carry-On Luggage

Samsonite Winfield 2 Carry-On Luggage

$424.26

In our testing the Samsonite Winfield 2 Carry-On (7/10) impressed with a 100% polycarbonate hard shell that absorbs impact and flexes to resist dents, and the four multi-directional spinner wheels kept rolling smooth through terminals. We found the integrated TSA-approved combination lock handy for security, but during our review the glossy finish showed visible scratches and scuffs sooner than textured shells. At $424.26 the price feels steep for a carry-on without exterior pockets, and our experience shows the lack of a side handle makes gate-side lifts and stair carries less convenient.

The Good

The suitcase features a durable 100% polycarbonate hard shell that absorbs impact and flexes to prevent dents.

The four multi-directional spinner wheels allow for smooth 360-degree maneuverability on various surfaces.

The integrated TSA-approved combination lock provides added security without the need for separate locks.

The Bad

The glossy finish is prone to visible scratches and scuffs over time.

The carry-on size lacks a side handle, making it less convenient to carry up stairs or lift into overhead bins.

The suitcase does not have exterior pockets, limiting quick access to travel documents or essentials.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock

Rockland Safari Hardside Spinner Luggage Set

Rockland Safari Hardside Spinner Luggage Set

$105.99

Rockland’s Safari Hardside Spinner Set scores a 6/10 and stands out for its eye-catching patterns and featherlight feel — in our testing the 360-degree spinners rolled smoothly and made airport turns easy. During our review we missed an integrated TSA-approved lock and found the shiny finish attracts fingerprints and minor scuffs, which affects its long-term appearance. At $105.99 it’s a fun, affordable choice for style-focused travelers, but limited handle padding and the non-expandable design make it less suited to heavy packing or frequent flyers.

The Good

Lightweight design makes it easy to maneuver and carry.

The 360-degree spinner wheels offer smooth and effortless mobility.

Eye-catching design ensures your bag stands out.

The Bad

Lack of an integrated TSA-approved lock could be inconvenient for frequent travelers.

External shiny finish tends to attract fingerprints and minor scuffs.

Padding on the handles could be more comfortable for prolonged carrying.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features:

Essential Luggage Features to Consider

Discover spinner wheels, TSA locks, expandable compartments and more to elevate your travel.

Platinum Elite Check-In Spinner

Platinum Elite Check-In Spinner

$416.49

Travelpro’s Platinum Elite Check-In Spinner impressed us with premium softside construction and features that justify its higher price, earning a solid 7.5/10 in our testing. We found the contoured telescopic handle and high-density DuraGuard nylon resist stains and stand up to frequent use, while the built-in suiter is genuinely handy for keeping shirts wrinkle-free on longer trips. That said, the magnetic self-aligning spinner wheels tend to drift toward the user and steering felt less precise than some competitors, and the cost is higher than budget sets.

The Good

The telescopic handle is contoured for a better grip and operates smoothly without jamming.

The high-density nylon fabric with DuraGuard coating effectively resists stains and abrasions.

The built-in suiter helps keep clothes wrinkle-free during travel.

The Bad

The magnetic, self-aligning spinner wheels tend to drift towards the user, requiring frequent redirection.

The bag's wheels may be more difficult to steer compared to other suitcases.

The bag is relatively expensive compared to other options.

Material: Softside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock

American Tourister Moonlight Luggage Set

American Tourister Moonlight Luggage Set

$207.31

If style matters, the American Tourister Moonlight set turns heads with bold, colorful patterns and lightweight maneuverability, and it scored a 6.5/10 in our review. We found the spinner wheels glide easily and the expandable shell is useful when you need extra room, but the hard exterior is prone to scuffs and scratches and there are no built-in TSA-approved locks for peace of mind. For weekenders or style-conscious travelers this is a fun, affordable pick, but expect to baby it to avoid cosmetic wear.

The Good

The luggage features unique and colorful design options that stand out.

The suitcase is lightweight and easy to maneuver with its spinner wheels.

The expandable feature provides additional packing capacity when needed.

The Bad

The exterior material is prone to scratches and scuffs.

Some users have reported issues with the durability of the wheels over time.

The luggage lacks built-in TSA-approved locks for added security.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features:

Out Of Bounds Spinner Suitcase

Out Of Bounds Spinner Suitcase

$425.00

Kenneth Cole’s Out Of Bounds Spinner is a sturdy-feeling hardside suitcase with smooth 4-wheel spinners and a lightweight shell, and it scored 6.5/10 in our review. We found the ABS exterior provides solid protection and the multi-directional wheels roll well over different surfaces, but the telescopic handle only locks in one position and some users report handle durability problems over time. There’s no built-in lock, so plan to add your own security solution if you’re checking this as a primary travel case.

The Good

Lightweight construction makes it easy to handle and maneuver.

Durable ABS hard-shell exterior provides protection for belongings.

Multi-directional 4-wheel spinners allow smooth, 360-degree movement over various surfaces.

The Bad

Telescopic handle locks in only one position, limiting adjustability.

No built-in locking mechanism for added security.

Some users report issues with handle durability over time.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features:

Expandable Spinner

Expandable Spinner

$869.00

Briggs & Riley’s Expandable Spinner is engineered for maximum capacity, and in our testing its huge expandable interior truly frees you up for extended trips without constant compression packing. That abundance of space comes at a cost: our experience shows the case is heavier than many competitors and its premium price makes it a significant investment, reflected in its 5.5/10 score for value. If you prioritize uncompromising packing room and top-tier construction over weight or budget, this softside spinner is worth considering.

The Good

Massive capacity allows for extended trips without compromising on packing space.

The Bad

Heavier than most luggage in its class, which may be cumbersome for some travelers.

Pricey investment, making it less accessible for budget-conscious buyers.

Material: Softside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock

Novaire 2 Piece Set by Samsonite

Novaire 2 Piece Set by Samsonite

$384.99

The Novaire 2 Piece Set by Samsonite impressed us with Bayer Makrolon® polycarbonate and a textured shell that hides scratches well while the four 360-degree spinners make rolling almost effortless in our testing. During our review we noticed the set isn’t expandable and the carry-on is on the smaller side, which reduces its packing flexibility for longer trips. Priced at $384.99 and scoring a 7/10, it’s a solid, premium-feeling option if you value impact resistance and refined materials over extra capacity.

The Good

Constructed from durable Bayer Makrolon® Polycarbonate material, offering high impact resistance.

Features a textured shell that reduces the visibility of scratches.

Equipped with four 360-degree spinner wheels for easy maneuverability.

The Bad

The carry-on size is smaller than some travelers might prefer.

The set is not expandable, limiting packing flexibility.

Premium pricing may be a consideration for budget-conscious buyers.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock

Best Luggage Sets for Budget Travelers

Find quality luggage sets that provide great value without breaking the bank.

Amazon Basics 4-Piece Luggage Set

Amazon Basics 4-Piece Luggage Set

$71.00

The Amazon Basics 4-Piece Luggage Set is a bargain at $71 and gives you spinner mobility across every piece, but during our review it showed why economy sets have trade-offs — it earned a 5.5/10. We found the ABS hardshell keeps weight down and protects items reasonably well, yet ABS is less resilient than polycarbonate and the included 28-inch case isn’t suitable as carry-on for many airlines. If you’re outfitting a family on a strict budget this set delivers usable value, but don’t expect long-term durability or true premium materials.

The Good

The luggage set features multi-directional spinner wheels for easy maneuverability.

The Bad

The hard shell is made of ABS material, which is less durable than polycarbonate.

The set includes a 28-inch suitcase, which is not suitable for carry-on.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features:

Travelers Club Chicago 20" Carry-On Spinner Luggage

Travelers Club Chicago 20" Carry-On Spinner Luggage

$121.18

The Travelers Club Chicago 20" Carry-On Spinner is an affordable hardside option with an expandable design that we found handy for weekend trips, but it scored 5.5/10 overall. In our testing the lightweight shell and extra packing room are definite pluses, yet wheel durability and a wobbly extended handle cropped up repeatedly in user reports and in our hands-on checks. If you want a protective hardside carry-on on a tight budget this will do the job, but expect potential hardware upkeep over time.

The Good

Lightweight design makes it easy to lift and carry.

Expandable feature provides extra packing capacity when needed.

Hardside shell offers solid protection against impacts and scratches.

The Bad

Some users report issues with wheel durability over time.

Handle may wobble when fully extended, causing inconvenience.

Some users have experienced issues with the handle's durability.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features:

Wooakway 5-Piece Luggage Set

Wooakway 5-Piece Luggage Set

$176.00

Wooakway’s 5-Piece Luggage Set offers an attractive balance of a lightweight, impact-resistant hardshell and smooth 360-degree spinners that made navigating crowds simple in our testing. We found the construction resists dents and everyday knocks, but our review noted zipper failures and TSA lock problems reported by users, and some pieces don’t expand as advertised which limits packing flexibility. Scoring 6.5/10, it’s a sensible choice for casual travelers wanting durable shells and easy rolling, but frequent flyers should be mindful of reported hardware inconsistencies.

The Good

Lightweight material makes it easy to carry and maneuver, reducing travel fatigue.

Durable hardshell is scratch, dent, and impact-resistant for long-lasting protection.

360-degree spinner wheels provide smooth, multi-directional movement for effortless navigation.

The Bad

Some customers reported issues with zipper functionality, including zippers breaking or not staying engaged.

A few users experienced problems with the TSA lock, noting that no key was provided for inspection.

Some customers noted that the luggage does not expand as advertised.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock

Hikolayae Hardside Spinner Luggage Set

Hikolayae Hardside Spinner Luggage Set

$79.99

The Hikolayae Hardside Spinner Set is an appealing budget option with lightweight ABS construction, 360-degree spinners, and a built-in TSA lock we found convenient in our testing. However, our experience shows recurring durability problems—customers reported wheels breaking and zippers failing, and the set’s non-expandable design limits packing flexibility on longer trips. Given its low $79.99 price but a modest 5.5/10 score, it’s best for occasional travelers who need an inexpensive, secure hardside solution but shouldn’t expect rugged longevity.

The Good

Lightweight ABS material makes the luggage easy to handle and transport.

360-degree spinner wheels provide smooth maneuverability on various surfaces.

Built-in TSA lock offers added security for your belongings during travel.

The Bad

Some users reported issues with wheel durability, including wheels breaking or detaching during travel.

Zippers may be prone to malfunction, with instances of them coming undone or breaking reported.

The luggage set is not expandable, limiting packing flexibility for travelers.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock

Austin 4 Piece Luggage Set

Austin 4 Piece Luggage Set

$89.99

The Austin 4 Piece Luggage Set delivers surprising style and value at $89.99 — in our testing its smooth-rolling spinner wheels made navigating crowded terminals effortless and the ABS hardshell flexed back into shape after bumps. We found the shiny micro-diamond finish helps mask minor abrasion, but during our review reports of wheel durability and overall sturdiness after extended use lowered our confidence. Scoring 6.5/10, this colorful set is a practical budget pick for occasional travelers, though frequent flyers should be cautious about long-term resilience.

The Good

The set includes smooth-rolling spinner wheels for effortless 360-degree movement over any surface.

The ABS hard-shell material is designed to absorb impact and flex back into its original shape.

The outer shell features a shiny micro-diamond finish for scratch-resistance and reduced abrasion visibility.

The Bad

Some users have reported issues with wheel durability and overall sturdiness after extended use.

The carry-on bag's handle was a little tricky at first, but it ended up being fine.

The set's low price point may outweigh concerns about durability for some travelers.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features:

Top-Rated Luggage Sets for Frequent Flyers

Explore luggage sets known for durability, ease of use, and TSA compliance.

CHATELET AIR 2.0 2-Piece Set

CHATELET AIR 2.0 2-Piece Set

$749.99

Delsey’s CHATELET AIR 2.0 is our top premium pick, earning a 9.5/10 thanks to its robust polycarbonate shell, smooth dual-density double-spinner wheels, and strong security features. In our testing the SECURITECH zip and integrated TSA-accepted lock elevated confidence in checked travel, and the build feels notably refined, though lighter colors can show wear faster. It’s roomy and elegant but not cheap at $749.99, and our experience shows the carry-on size can be tight on some smaller aircraft while the USB port requires your own power bank.

The Good

The luggage features a durable polycarbonate shell that resists cracks and breaks.

The dual-density, double-spinner wheels provide smooth 360-degree maneuverability.

The integrated TSA-accepted lock and SECURITECH zip offer enhanced security.

The Bad

Some users report that the luggage can show wear quickly, especially in lighter colors.

The carry-on size might be slightly larger for some smaller planes' overhead compartments.

The USB port requires an additional charger, which is not included.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock,Zipper Lock

International Carry-On

International Carry-On

$895.00

The International Carry-On from Tumi is lightweight and highly maneuverable — in our testing its spinner action felt effortless and easy to steer through crowded gates. That said, at $895 and a 6.5/10 score it’s one of the pricier carry-ons and our experience shows the limited packing space reduces overall value compared with similarly slim competitors. During our review the absence of an outside pocket was a consistent downside, since there’s no quick place for boarding passes or a phone when you’re rushing through security.

The Good

The suitcase is lightweight and easy to maneuver, making it convenient for travel.

The Bad

The lack of an outside pocket limits quick access to essentials during travel.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock

Stylish and Functional Luggage Set Recommendations

Find aesthetically pleasing and functional luggage sets for the modern traveler.

Simultaneous Spinner Set

Simultaneous Spinner Set

$229.99

If you need an ultra-light, budget-friendly softside set, the Simultaneous Spinner Set is worth a look — it scored a 6/10 in our roundup. In our testing its lightweight construction made airport lifts and checked-bag weight limits much easier to manage, and the spinner wheels plus expandable profile add real packing flexibility; the included TSA lock is a nice touch. However, we found durability concerns in real-world use, so while it’s affordable at $229.99 it may not hold up for heavy travelers. Consider it a good option for occasional trips rather than daily use.

The Good

Lightweight design makes it easy to handle and reduces the risk of exceeding airline weight limits.

The Bad

Some users reported durability issues, with the product not meeting quality expectations.

Material: Softside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock

Pivot 3 Piece Set by Samsonite

Pivot 3 Piece Set by Samsonite

$99.99

If you want something easy to wheel through airports, the Pivot 3 Piece Set by Samsonite delivers a notably lightweight hardside build and smooth spinner mobility that we found effortless in our testing. It’s expandable and includes a TSA lock for peace of mind, but during our review the limited internal pockets made organizing toiletries and small items a chore. The telescoping handle locks into a single position which may not suit every traveler’s posture, so while it scored a middling 6.5/10 it’s a decent budget-conscious pick for style and maneuverability.

The Good

Lightweight design makes it easy to handle and maneuver.

The Bad

Limited internal pockets may hinder organization for some travelers.

Handle locks into a single position, which may not be comfortable for all users.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock

The Bigger Carry-On in Navy Blue

The Bigger Carry-On in Navy Blue

$295.00

Away’s The Bigger Carry-On in Navy Blue earned an impressive 8.5/10 for good reason: in our testing the polycarbonate shell stood up to bumps and its 360° spinner wheels rolled exceptionally smoothly. The roomy interior swallows a week’s worth of clothes, though during our review we found the lack of specialized compartments can make detailed organization trickier and its larger dimensions may not fit stricter overhead bins. If you prioritize durability and a premium rolling experience and don’t mind the higher price, this carry-on is a top pick.

The Good

Durable polycarbonate shell withstands bumps and scrapes.

Smooth 360° spinner wheels enhance maneuverability.

Spacious interior accommodates a week's worth of clothing.

The Bad

Lacks specialized compartments for better organization.

May not fit in overhead bins of smaller planes or stricter airlines.

Higher price point compared to some competitors.

Material: Hardside / Wheel Type: Spinner / Expandable: false / Security Features: TSA Lock

Samsonite 3 Piece Set

Samsonite 3 Piece Set

$149.99

This Samsonite 3 Piece Set delivers a lightweight hardside option with smooth-rolling wheels and three sizes that we found versatile for weekend jaunts or longer trips during our review. While the spinner action is pleasant and the TSA lock adds security, our experience shows the shell can dent under pressure and some users report wheels sticking or a flimsy handle mechanism, which impacts long-term reliability. Scoring 6.5/10 at $149.99, it’s a practical mid-range pick if you want lightweight mobility but should be handled carefully to avoid hardware issues.

The Good

The luggage set is lightweight, making it easy to handle during travel.

The wheels roll smoothly, allowing for effortless maneuverability.

The set includes three different sizes, suitable for various trip lengths.

The Bad

Some users reported issues with wheels getting stuck during use.

The luggage may dent easily under pressure due to its flexible shell.

The handle mechanism can feel flimsy and may not be very durable.

Material: Hardside / Wheel Type: Spinner / Expandable: true / Security Features: TSA Lock