Athalon has taken their standard boot bag and made some great improvements. Most notably is a heating element inside the bag that heat to warm and dry the boots overnight or on the way to the ski resort. The become extremely easy to put on and they fit better all day. The bag also has features like hidden backpack straps and an expandable side compartment for helmets. The bag is carry-on size to help ensure your ski boots show up at the same place you do.