About these items:Airline-Approved Pet Carrier: Designed to meet TSA regulations, this rolling pet carrier fits under most airline seats, making air travel easy and stress-free for small pets. It accommodates pets up to 25 lbs, with dimensions ranging from 17.5" x 11.2" x 11.4" to 25.5" x 14.1" x 14.5" depending on the model. Always check airline regulations before departure.Durable Construction: Made from 600D Oxford cloth, the carrier is built to withstand long-term use while securely carrying your pet. With a sturdy frame and long-lasting materials, it is perfect for car travel, vet visits, and other adventures with your small furry companion.Breathable and Comfortable: Featuring mesh windows on all sides, these carriers provide excellent ventilation and visibility for your pet. The back and shoulder straps are padded for extra comfort during extended trips. Some models include side pockets for convenient storage of pet supplies and a folding pet bowl.Smooth Mobility: Equipped with 360° double-layered, wear-resistant wheels (2.1-2.3 inches in diameter), these carriers ensure a smooth, bump-free ride on various road surfaces. The multi-directional wheels enhance ease of movement, and some models feature lockable wheels for stability when stationary.Versatile Carrying Options: These pet carriers offer multiple carrying methods: hand-held, shoulder-worn, or wheeled with an adjustable aluminum alloy pull rod (3 to 4 levels). Self-locking zippers prevent escapes, while detachable allows for easy storage and handling.Key Differences:Max Load Capacity:Model JW-XB21212517: 25 lbsModel JW-XB21212255: 22 lbsModel JW-XB21212519: 18 lbsModel JW-XB21212518: 35 lbsBag Size:Model JW-XB21212517: 17.5" x 11.2" x 11.4" / 445 x 285 x 290 mmModel JW-XB21212255: 17.5" x 12.2" x 11.8" / 445 x 310 x 300 mmModel JW-XB21212519: 16.7" x 13.9" x 11" / 425 x 355 x 280 mmModel JW-XB21212518: 25.5" x 14.1" x 14.5" / 650 x 360 x 370 mmMesh Windows:Model JW-XB21212517: 4 mesh windowsModel JW-XB21212255: 5 mesh windowsModel JW-XB21212519: 3 mesh windowsModel JW-XB21212518: 5 mesh windowsStorage Pockets:Model JW-XB21212517: 1 storage pocketModel JW-XB21212255: 2 storage pocketsModel JW-XB21212519: 5 storage pocketsModel JW-XB21212518: 2 storage pocketsWheel Diameter:Model JW-XB21212517: 2.3 in / 6 cmModel JW-XB21212255: 2.1 in / 5.5 cmModel JW-XB21212519: 2.1 in / 5.5 cmModel JW-XB21212518: 2.3 in / 6 cmSpecifications:Item Model Number:JW-XB21212517: Rolling Pet CarrierJW-XB21212255: Rolling Pet CarrierJW-XB21212519: Rolling Pet CarrierJW-XB21212518: Rolling Pet CarrierMax Load Capacity:JW-XB21212517: 25 lbs / 11.3 kgJW-XB21212255: 22 lbs / 9.9 kgJW-XB21212519: 18 lbs / 8.1 kgJW-XB21212518: 35 lbs / 15.8 kgProduct Weight:JW-XB21212517: 5.9 lbs / 2.7 kgJW-XB21212255: 6.1 lbs / 2.8 kgJW-XB21212519: 5.5 lbs / 2.5 kgJW-XB21212518: 7.9 lbs / 3.6 kgDimensions:JW-XB21212517: 18" x 11" x 11"JW-XB21212255: 18" x 12" x 12"JW-XB21212519: 13.4" x 11" x 16.5"JW-XB21212518: 25.5" x 14.1" x 14.5"Bag Size:JW-XB21212517: 17.5" x 11.2" x 11.4" / 445 x 285 x 290 mmJW-XB21212255: 17.5" x 12.2" x 11.8" / 445 x 310 x 300 mmJW-XB21212519: 16.7" x 13.9" x 11" / 425 x 355 x 280 mmJW-XB21212518: 25.5" x 14.1" x 14.5" / 650 x 360 x 370 mmMain Material: 600D Oxford ClothPull Rod Material: Aluminum AlloyZipper: Self-locking ZipperStorage Pockets:JW-XB21212517: 1 storage pocketJW-XB21212255: 2 storage pocketsJW-XB21212519: 5 storage pocketsJW-XB21212518: 2 storage pocketsMesh Windows:JW-XB21212517: 4 mesh windowsJW-XB21212255: 5 mesh windowsJW-XB21212519: 3 mesh windowsJW-XB21212518: 5 mesh windowsNumber of Wheels: 4Wheel Diameter:JW-XB21212517: 2.3 in / 6 cmJW-XB21212255: 2.1 in / 5.5 cmJW-XB21212519: 2.1 in / 5.5 cmJW-XB21212518: 2.3 in / 6 cmPackage Contents:All Models:1 x Rolling Pet Carrier1 x Folding Bowl