Ensure you're not left out on the battlefield stranded without ammo, by picking yourself up an extra 330-round magazine for your compatible M4 rifle. Keep your M4 firing continuously throughout the battle with this High Capacity magazine option from Classic Army. Simply fill the storage compartment in the back of the magazine, and wind the gear on the bottom of the magazine to feed BBs into the spring loaded feeding area. These magazines are each made with high quality, durable polymer which helps keep the overall weight low and makes carrying extra magazines a breeze. The specially designed exterior texture gives maximum grip and stability when hastily changing your magazine, and offers a more unique look than your classic AEG magazine. Due to the design of all High-Capacity Magazines, they function better once they are broken in and the spring becomes more flexible and can be manually broken in by spraying some light silicone oil into the magazine and loading then unloading the magazine couples times allowing perfectly smooth function, every time. Get back on the battlefield confident you are ready for whatever may come your way.