BCM® Low Profile Gas Block for AR15, M16, M4, M4A1. Machined of steel with phosphate finish. Manufactured within very tight Mil-Spec tolerances on all ID's. Barrel ID honed after finish per USGI TDP. Made by Bravo Company MFG, Inc. with set screw mounting.

Available for 0.625” and 0.750” barrel diameters.

Set Screws for both sizes are Steel 10-32 x 3/16 Knurled Cup Point.