Adding a Multi-Comp Compensator to your 1911 Auto is as fast and easy as changing out the barrel bushing. Since the Multi-Comp can be used with your stock barrel, you have greater flexibility with your pistol at minimal cost. The Multi-Comp works on all Government length (5") 1911 Autos with .576 - .580 muzzle O.D. in calibers up to and including .45 ACP. Requires Wilson Combat #148,5 Two-Piece Guide Rod or stock recoil spring plug shortened to 1.2".