Seekins Precision AR ATC Muzzle Brake, 223 Rem/556NATO, Melonited Black Finish, 1/2X28 Threads 11510035 The Seekins Precision Advanced Tactical Compensator was engineered to be the most innovative" best performing compensator available. Gases behave like a fluid. Using CFD (Computational fluid dynamics) analysis software" Seekins designed the optimal port configuration and quantity for maximum reduction of felt recoil and muzzle rise. Instead of allowing the first port to do the majority of the work" proprietary front facing ports spread out the gas. This novel port design minimizes the amount of recoil felt and reduces muzzle rise without the need for ports on top. The incredible performance of the ATC allows faster follow up shots and quicker target transitions. No other compensator is as easy to install. Instead of using a crush washer" included is a Timing Nut to make installation and removal for making cleaning a breeze. Peel washers" crush washers and repeated trial and error for proper alignment are no longer necessary. No special gunsmithing is required to install.