"ExpandabilityThe expandable back provides extra space for your pet to create a comfortable area for increased air circulation and more comfortable movement. Ventilation and Light - 1. The backpack's The top can be opened to let your pet's head stick out, open the mesh zipper for breathability and visibility, and apply sunscreen to prevent direct sunlight.Three-sided acrylic panel design, good light transmission, ensure air circulation and avoid overheating .Adjustable Shoulder StrapsLarge design with adjustable shoulder pads to help reduce load and improve comfort, with two retractable buckles at the top and bottom to prevent the shoulder straps from deflecting, thus maintaining the stability of the pack. Summer and Winter UseRemovable solid bottom, compressible, can be used on both sides: the bottom pad is made of flannel. In winter, pets can stay indoors warm and comfortable; the other side is Oxford designed for summer, cool and breathable It can be disassembled and washed separately, allowing your pet to sit or sleep comfortably.Storage and Safety-1.Made of high quality Oxford cloth, waterproof, scratch-resistant, eco-friendly, non-toxic, non-irritating odor -2. There are two storage pockets on the side of the backpack, one for garbage bags and dispensers, two for bottle holders, and one for small items such as mobile phone wallets. -3. Built-in retractable hook safety rope with leak-proof zipper"