LARGE SIZE - Measures approximately 15.7*10*18.5inch (L x W x H). This pet backpack carrier is designed for small and medium sized dogs weighing up to 20 lbs.; cat, rabbit and other small animal up to 22 lbs. (NOTE: Please measure the size and weight of your cat dog before purchasing this product, do not select the backpack size based on weight only, please reference your pet's length and height in selecting a backpack size). LENGTH: neck to base of tail; HEIGHT: floor to top of shoulder. EASY INTERACTION & VENTILATION DESIGN -Three side was made of ventilation PVC mesh, this cat travel carrier can ensure that the air is well circulated when the pet in the backpack, let your pet breathe freely and relax, and add curtains to prevent your cats/dogs from sun, provide a safe privacy and reduce pet's stress response to external things when travelling. You can also roll up the front curtain to increase breathability. COMFORTABLE AND CONVENIENCE - This dog travel carrier helps you hands-free carrying and makes it the most safe and convenient dog hiking backpack for your travel. This dog carrier backpacks comes with chest buckles which helps to reduce the burden and keeps the shoulder straps from slipping while pet moving. Built-in double-sided usable support pad, you can choose the more suitable side according to the season and temperature. And it can be removed and washed separately!