DESC: Phoenix Pack The Phoenix back pack is a uniquely designed frameless pack with a padded back and body. The contoured "S" shoulder straps have a detachable sternum strap and torso lumbar support. The inside back has a pouch to fit an optional 100 oz. HydraStorm Hydration System with our Tube Routing Systemr to feed the drink tube out the top and over either shoulder. This feature allows the user to efficiently carry 2.5 qts. of hot or cold liquid to drink on the move.