Asura Dynamics CNC Aluminum Bolt Carrier for Marui M4 GBB (Gold) 
CNC Aluminum Construction ( Rigid, Durable and Lightweight ) 
Suitable for Tokyo Marui MWS M4 Series Airsoft Gas Blow Back GBB Rifle
which will enable a higher rate of fire while reducing wear and tear between parts, the inserted steel reinforcement for bolt stop also enables a firm bolt stop action
Distinctive-looking, smooth surface won