Madbull Top Rail Gas Block for M4/M16 series

Madbull Top Rail Gas Block Full Metal Construction Convert your Gas Block with RIS ready in just seconds Take off your original M4 front sight and put on fancy gas block. Attach on M4/M16 Type Barrel for firm attachment 20mm Flat Top Rail allow attachment of tactical Laser, Flashlight..etc Suitable for Marui Compatible M4/M16 Airsoft Barrel