This is a Bravo Company Compensator known as the Compensator chambered in 556NATO, model BCM-GFC-MOD-0-556.
Designed to have much less side blast and noise associated with typical compensators. Makes it perfect for working in teams for CQB. It is a compensator that is built for the 21st Century Gunfighter!
Features:
Nitride treated for maximum corrosion resistance
Includes a Crush Washer
Exterior dimensions consistent with Mil-specs for mounting suppressors