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 device has been classified as a non-flash suppressing device by the BATFE. Due to changes with the Gemtech HALO mounting device, the FSC556 is no longer compatible with the 2009 or newer HALO suppressors. The device will continue to ship with a peel washer. This unit is 2.10" in length, .865" (22mm) in diameter and is threaded 1/2x28 RH.