For FAMAS Airsoft Electric Rifle (item # PS-40901). Holds 300 rounds. Easy to fill, just pour in 300 rounds through the top hatch. Easy winding spring dial on the bottom keeps tension on the ammo for smooth feeding. Also compatible with Tokyo Marui FAMAS. Attention customers! The door to the BB loading reservoir is difficult to open with just your fingers. We recommend using a firm, thin object to lift the lid open to avoid breaking your nails or hurting your hands.