.625 BCM Low Profile Gas Block for AR15, M16, M4, M4A1. 

• Machined of steel
• Phosphate finish
• For .625 barrels.
• 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.