Made in the usa, the the apollo s from ultradyne provides competition level recoil reduction and muzzle control.It is perfect for shooters who want drastic recoil reduction with less perceived blast.By using a scientific approach and studying thousands of recoil events, ultradyne engineers have struck a balance between extreme recoil reduction, virtual elimination of muzzle rise, and less aggressive venting of gas.A timing nut is included for easy installation.Finish: Black NitrideModel: ApolloMaterial: 416 Stainless SteelThread Pattern: 5/8"-24 tpi