Knight's Armament Airsoft Stoner LMG 1200rd Electric Box Magazine with Woodland camouflage cover. A spring powered flip-up door on the top of the box mag reveals a filling port BBs can be poured into. A spring steel retention clip keeps the mag securely attached to the Stoner LMG with virtually no wobble. The coiled feeding tube brings BBs from the magazine to the LMG and is powered by a replaceable 9v battery stored on the bottom of the box magazine. A selector switch can toggle through off, automatic winding, and always on modes. The camo patterned protective bag is held securely closed by a buttonable zipper as well.