The PTS EPM-G AEG for G36 AEG rifles are the best mid caps on the market for the platform, featuring a constant-curve internal geometry for reliable feeding. It utilizes similar internal design to the legendary EPM magazines, which means these mags feed incredibly smoothly and at high rates of fire! These do NOT fit M4, but are only for compatable G36 Replicas. Compatibility: Fits Tokyo Marui, Classic Army, JG, SRC, Umarex, Echo1 and other G36, XM8, SL9, SL8 and compatible G36 series Airsoft AEG