1. and Expandable:Our pet carrier backpack with an expandable back allows your little cutie to move around more comfortably and reduces the anxiety.When not in use, it can be folded for storage to save space.This pet backpack is roomy and will fit most cats, small dogs, and most other small/medium sized pets 2. Comfortable and Breathable:The cat backpack carrier has a removable firm bottom that can be unzipped and features soft, comfy padding for your pet to sit or sleep on comfortably.The entire structure is crafted with a breathable mesh material to ensure proper ventilation and circulation of air 3. Available in All Seasons: Available in All Seasons: The top of the cat backpack can be opened, for your pet to stick their head out off, you can snap on the shade cover to protect from the sun.The sides are internally made with a windstopper that pulls up to keep you warm or opened for ventilation, suitable for multiple seasons 4. Multi-storage Design:There are two bags for storage on the side of the pet bag, one for waste bags and dispensers and water bottle holders, and another for storing mobile phones, wallets, and other small items