【 EXPANDABLE & FOLDABLE 】 This pet carrier (17.3x13.6x10.4in) with an expandable back design gives your pet more space (increase by 90%) to rest and increase air circulation, allows your pet to move around more comfortably and reduces the anxiety. When you don’t need to use it, the folded pet backpack will only take up very little space. Airline approved? Each airline sets their own specific requirements, so it is advised to check with your airline of choice. 【 MAXIMUM AIR CIRCULATION & MULTIPLE ENTRANCES 】 Comes with 4-side breathable mesh windows, giving plenty of air for pets. Makes it easy for you to observe the movement of your pets while they are enjoying the scenery outside. With zippers on both top and front, your lovely pets can be put in and out of our pet carrier backpack easily. 【 SHOCK ABSORPTION DESIGN 】 Honeycomb mesh elastic sponge back cushion, breathable, decompression and shock resistance, release pressure and travel easily. Widened design, adjustable shoulder pad to help reduce load and increase comfort, two retractable buckles on the top and bottom of the cat backpack to prevent shoulder strap deviation and maintain the stability of the dog carrier.