The G&G TR16 GMS MK19 M4 AEG Airsoft features a metal construction, including a metal receiver, metal 9-inch M Lok handguard, metal outer barrel with muzzle brake, metal stock pipe with polymer GOS-V15 stock, polymer flip-up fiber optic front & rear sight, polymer pistol grip, polymer GOM V4 30-round magazine. The magazine comes with dummy rounds to give the magazine a more realistic feel, along with metal small parts such as magazine releases, ambidextrous selector, charging handle & bolt catch. Internally, it is equipped with an Ifrit 25K Motor-Long Axis orange (25000rpm), G2 8mm ball bearing, and a built-in GATE ASTER V2 SE ECU.