The MDP or Magazine Dispenser Pack is a pack worn around a soldier’s waist, much like a reverse cummerbund in that it wraps around to the flank from the back. Able to hold four magazines, each pack works much like a large magazine itself, forcing a new round into the ready position once its predecessor has been removed. Much like a weapon, the MDP has a ‘cocking’ lever that upon loading is drawn to the rear, containing the spring and follower within a door forming the closed end of the pack. The cocking lever is twisted to lock the spring in place and the door opened to load the magazines. Once loaded the door is closed and the spring reengaged, pushing the follower against the last mag. With every removed magazine, the spring releases tension and feeds the next into position. Four-unit MDPs are the most commonly deployed, but larger eight- and-ten unit variants are available, particularly to expeditionary assault troops like marines. These models are worn around the back of the belt.