A high capacity replacement of the standard magazine for the Marui M16 series rifle. Originally styled after the magazine for the M16VN though used by many who modify their M16 series rifle into a sniper system, since the shorter magazine allows greater ground clearance for sniper shooting. Fits M4, M4 RIS, SR16, M16A1, M16A2, M733, M16VN, and CAR15. Large thumb dial on bottom of magazine allows you to wind it up and feed 190 rounds of BBs into your AEG. Full metal construction.