SureFire Suppressor Adapter/Muzzle Brake is designed for M4 and M16 weapons with 1/2-28 muzzle threads. The patented Impulse Diffusion design minimizes side blast and rear-directed concussion effects. Precision machined from heat-treated stainless steel bar stock, it features high-precision single-point cut threads for optimum thread interface.The SFMB-556-1/2-28 muzzle brake has a black Ionbond DLC coating which provides protection under harsh conditions and facilitates cleaning. Additionally, it serves as a mounting adapter for SureFire SOCOM Series 5.56 mm Fast-Attach suppressors. A rear labyrinth seal helps reduce carbon buildup in the indexing system.