Ski-Doo 280000307 Summit Tunnel Backpack Bag - 28 Liter Capacity Utilizes a patent-pending cleat and bag retaining system that fully integrates into the platforms Clips onto sled and includes a compartment for the Ski-Doo shovel Chassis are pre-marked for easier installation of bags on the tunnel Quick-disconnect system instantly transforms the bag into a backpack 28-liter (7.4 US gallons) capacity bag