Open the chest and back, let the pet's front legs pass through the two holes on the chest and back, then close both sides of the chest and back, stick the Velcro, and fasten the three pronged buckle to complete the installation. For the other chest and back, put the pet's head into the loop of the chest and back, with colored fabric facing down, wrap around the pet's chest, and lock the three pronged buckle on both sides to complete the installation Choose the appropriate style based on your pet's weight and body shape, and let your pet wear a comfortable chest and back style. The checkered chest and back style is suitable for small dogs and cats, while the I-shaped style is suitable for medium and large dogs These two chest and back sizes are available in five sizes: XS, S, M, L, and XL. XS and S sizes are only available in orange and pink, suitable for pets weighing less than 6.6 pounds. The checkered version has a maximum weight of 22 pounds, while the X-shaped chest and back has a maximum weight of 99 pounds. Please choose the appropriate chest and back according to your pet's weight The chest strap is made of nylon material, paired with a mesh surface, which is breathable and comfortable to wear. The wrapping surface is large and has obvious identification features, which can provide certain protection during outdoor activities Suitable for various outdoor environments, paired with a 1.5m towing rope (dark blue, blue, orange, additional towing rope required) to enhance safety when going out, ensuring the safety of pets and owners Pet chest and back harness, suitable for outdoor activities and daily outings, with chest and back sizes of S, M, L, XL, XS, checkered pattern for a maximum weight of 22 pounds, X-shaped chest and back for a maximum weight of 99 pounds, easy to disassemble, quick to install, suitable for travel