Original to the AIR:

• Ventilated side panels for cooling
• Adjustable dual side pockets
• Sternum strap with avalanche whistle clip

New AIR 2 features include:

• Fully Updated Sizing (Each piece of the bag adjusted to ensure best fit)
• Wider Base 
• 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)
• More Adjustable Collar Enclosure
• Updated Logo