①. The fabric is environmentally friendly and durable, and the breathable material makes your pet feel free and safe, allowing your pet to be comfortable. ②. The front windshield provides good ventilation and visibility. Adjustable padded straps make it easier to carry, and the retractable straps with buckle keep the backpack stable. ③. The safe pull cord design: The safe buckle inside can be attached to your dog's collar, and the adjustable neck opening is designed to fit the circumference of your pet's neck and prevent them from jumping out. ④. There are 2 side pockets to store small items, which can free your hands. ⑤. It is suitable for cycling, traveling, shopping, hiking and other outdoor activities. ⑥. Dimensions: S - 11.81 x 13.7 x 5.51 inches / 30 x 35 x 14 cm (fits up to 2 kg); M - 13.7 x 15.7 x 6.7 inches / 35 x 40 x 17 cm (fits up to 4 kg). ⑦. This pet backpack can help you and your pet travel safer and more comfortably. You don't have to worry about losing your buddy or looking for them everywhere. ⑧. It is suitable for various extreme sports, such as hiking, camping, shopping, cycling, mountain climbing, etc. It allows your pet to enjoy a relaxing walk and keeps your hands free. ⑨. The mesh window design makes it easier for your pet to breathe and relax and enjoy the trip. ⑩. Reference size - S - 11.81 x 13.7 x 5.51 inches / 30 x 35 x 14 cm (fits up to 4.41 pounds / 2 kg); M - 13.7 x 15.7 x 6.7 inches / 35 x 40 x 17 cm (fits up to 8.82 pounds / 4 kg).