Ultra-lightweight: Even if small items are packed on the back, the whole weight will be light. This pet accessories will greatly reduce the feline's load. Truly achieve the ultimate lightweight. Zipper backpack design: 4.3*4.3*2 inch. When you go out for walking with your cat, you can put some small items into this pet zip bag, such as small paper towels, small garbage bags, key and bus card. With a backpack, you can go out and carry small items more conveniently with your pets. Size: This product is available in three sizes: S, M and L. S size for 1.5 kg - 3.5 kg, Suitable chest girth range is 28 - 42cm, Suitable neck girth range is 24 - 34cm. M size for 3.5 kg - 7.5 kg, Suitable chest girth range is 32 - 52cm, Suitable neck girth range is 28 - 44cm. L size for 7.5 kg - 10 kg, Suitable chest girth range is 48 - 68cm, Suitable neck girth range is 32 - 48cm. All parts are adjustable: The 1.5m traction rope with metal D-shaped buckle can be easily removed and replaced. Chest and neck collars part of harness are plastic buckle which can be adjusted according to the size of the pet. This product is very easy to operate. What you get: One cat vest harness with backpack, one traction pet leash. This pet harness is washable and suitable for many scenes, like jogging, training, walking. Walking out with this pet harness with backpack make you more convenient to take care of your little pets.