Grovtec US Inc GTHM316 G-Comp Muzzle Compensator 308 Cal 5/8"-24 tpi Black Nitride Steel The G-Comp Muzzle Compensator Is Designed To Redirect Propellant Gases And Counter Recoil And Muzzle Rise. These suppressors Are solidly Made With Steel Construction And a Black Nitride Finish. Model: G-Comp Material: Steel Thread Pattern: 5/8"-24 tpi Finish: Black Nitride