Ultradyne Apollo S Compensator AR-15 223/5.56 1/2-28in .975 Outside Diameter 416 SS Salt Bath Nitride Black. By using a scientific approach and studying thousands of recoil events Ultradyne engineers have struck a balance between extreme recoil reduction and less aggressive venting of gas without sacrificing the elimination of muzzle rise. The Apollo S is perfect for shooters who want drastic recoil reduction with less perceived blast. Like all Ultradyne muzzle devices a timing nut is included for easy installation. Specifications for Ultradyne Apollo S Compensator: Manufacturer: Ultradyne Color: Black Fabric/Material: 416 Stainless Steel Gun Make: AR Platform Gun Model: AR-15 Outer Diameter: 0.975 in Condition: New Condition Quality: Excellent Condition Details: Other Features of APOLLO S: Extreme Recoil Reduction Virtually Eliminates Muzzle Rise Manages Sonic Blast Pairs easily with the Dynamount Sighting System 416 Stainless Steel with Ultra Rugged SB Nitride Coating .975 Outside Diameter Competition Legal Shrouded Timing Nut Included Package Contents: Ultradyne Apollo S Compensator6.5mm5/8x24 What firearm models does the manufacturer say Ultradyne Apollo S Compensator is compatible with? The manufacturer says that Ultradyne Apollo S Compensator is compatible with AR-15Ultradyne UD10220: Apollo S Compensator Muzzle Brake AR-15 .223/5.56 1/2-28in .975 Outside Diameter 416 SS Salt Bath Nitride Black