This FSC556 Tactical Compensator has all of the compensation of the standard DNTC compensator combined with enough flash suppression to keep the flash out of your optics and line of sight.  This unit is 2.10" in length, .865" (22mm) in diameter and is threaded 1/2x28 RH. *This device has been classified as a non-flash suppressing device by the BATFE.