Modify Tech 300rd Polymer JMag (Jet Magazine) (Tracer Mag) with LED for M4/M16 Series

Modify Airsoft M16/M4 Tracer Magazine | J-Mag(JET Magazine) Features Rapid-load: Simply wind the arm 4 times to fully load all 300 BBs. Modular LED magazine: Easily installed to use tracer BBs for nighttime combat. Lightweight design: The magazine is of polymer composite to be tough and durable. User-friendly and time-saving design easy-to-use when you play war games.