Guards threads from damage and gives muzzle a finished look when compensator or flash hider isn't installed. Precision turned on a CNC lathe from steel barstock, then given crisp, diamond-pattern knurling that makes it easy to tighten and loosen protector on barrel. Available to fit 5/8"-24 threads. Mfg: Egw SPECS: 5/8"-24 - .800" (2cm) long, .960" (2.4cm) O.D.