【Expandable & Collapsible】- HALOVIE Pet Backpack with a large expandable back gives your pet more room to move around and effectively reduces their anxiety when you don't want them to walk anywhere. Collapsible design helps you to save space when not in use 【Breathability & Visibility】- There are tear-resistant breathable mesh on the front, top and 2 sides of the carrier backpack to maximum air circulation, non-toxic and non-smell, let your pet breathe freely and relax. The top of the backpack can be opened, for your cat/dog to stick their head out off 【Thicker Fabric & Sturdy Bottom】- Made of 100% premiun Oxford fabric (no poor ventilation plastic bubble), more durable and thicker than other inferior pet backpacks on the market. Extra add a reinforced base and a soft pad on the bottom, both are removable & washable and desighed with dual sided, one furry side for winter and the other side for summer