LARGE CAPACITY CAT CARRIER: The upper layer of the pet carrier is a pet organizer bag for cat supplies such as food, collars, leashes, etc. The lower layer is a large capacity space for pets up to 17LB. The middle divider can be removed. In addition, this dog backpack has 5 additional storage pockets. UPGRADED VENTILATION DESIGN: VANANSA pet carrier is designed with mesh on three sides to ensure air circulation and good permeability. On top of the mesh, our cat carrier backpack adds three curtains to protect against the wind and give your pet privacy. DOUBLE PROTECTION: Rolling pet carrier for small medium cats and dogs have an internal safety leash that can be attached to the collar. At the same time, the zippers of our cat carrier backpacks are lockable to prevent the cat from escaping. LIGHTWEIGHT & COMFORTABLE: Our dog carrier backpacks weight 8.6lb (backpack 6.2lb, trolley 2.4lb). The back cushion and adjustable shoulder straps of the large cat carrier are thickened and widened with high quality sponge. Chest buckles keep the pet trolley backpack stable. MULTIFUNCTIONAL USE: The dog travel carrier for small dogs has four 360° silent smooth wheels and a triple-adjustable aluminum trolley. The stroller and wheels are removable, so our pet carrier with wheels can be easily converted into a backpack, car seat and pet bed.