Made in the usa, the mercury has been meticulously engineered for the.223/5.56 caliber to provide superior recoil reduction and neutralize muzzle rise with a smooth, balanced release of blast energy.Progressive 90 side ports vent com-busting gases at intervals that spread out the recoil impulse for efficient, a timing nut is included for easy installation.Finish: Black NitrideModel: MercuryMaterial: 416 Stainless SteelThread Pattern: 1/2"-28 tpi