The AIR is a great place to start for your first pet-carrying adventure. This classic model is the most flexible, breathable and lightweight pet carrier in our catalog; perfect for shorter hikes, bike rides and any other quick trip or outing you can dream up. Like all K9 Sport Sack models, it was designed under the close direction of veterinarians, dog trainers and outdoor product engineers to be ergonomic, safe and strong. 30 LB/13 KG weight limit. K9 Sport Sack AIR Features: Ventilated cooling side panels. Over 5 different safety/failsafe features. Adjustable dual side pockets. Sternum strap avalanche whistle clip. Moisture wicking, ventilated shoulder straps.