DBoys M4 / M16 Metal 300rd High Capacity Airsoft AEG Magazine This hicap magazine is compatible with Echo 1, JG, AGM, ICS, DBoys, G&G, Classic Army and TM M4/M16 AEGs, including the G&G M4A1 Carbine Electric Blowback AEG Rifle M4/M16 high capacity airsoft magazine with metallic shell can hold up to 300 rounds Great for resistance against the elements and light debris. High capacity magazine stores neatly into all fitted M4/M16 magazine pouches and equipment systems. - Airsoft Use Only. Plasic BBs. Magazine locks into place and remains secure even during heavy gameplay.