The Air 2 is the backpack dog carrier people know best. Available in sizes XS-L, it is a durable, breathable mid-level backpack perfect for smaller to medium size dogs. The Air 2 is offered at a reasonable price while including the essential safety and comfort features needed for a comfortable experience. This backpack is recommended for intermediate grade walks, hikes, public transportation, and bike rides. The Air 2 is constructed with durable Cordura® fabric and form-fitting mesh on the sides for breathability. For Dogs Ranging 4-30 lbs (2-13 kgs) View More Sizing Instruction Features Ventilated side panels for cooling Adjustable dual side pockets Sternum strap with avalanche whistle clip Wide Base to accommodate your pet and its tail Updated Side Mesh New Side and Back Cinch Straps Updated Shoulder Strap Design (No More Popping Off Chest Clips) Fur Flap (No more zipping your dog's hair in the bag) Adjustable Collar Enclosure Compare K9 Sport Sack Carriers View Patent Info Safety All K9 Sport Sack carriers are specially developed under the close direction of animal professionals, veterinarians, dog trainers, and outdoor product engineers to be ergonomic, safe, and strong.