The Gate-LOK Flash Comp optimally combines the functions of three traditionally separate classes of devices- Muzzle Brakes, Tactical Compensators, and Flash Suppressors. The Gate-LOK Flash Comp achieved a perfect 5 out of 5 in National Tactical Officers Association testing to achieve the rare, coveted, NTOA Gold seal of approval granted to devices which achieve perfect evaluations. Compatible with the M4SD series Gate-LOK suppressor interface. The Flash Comp provides a sacrificial baffle to increase the service life of your silencer. It is also pre drilled, and 2.25 length for 14.5 to 16 permanently attached, Non-SBR, M4 carbine builds. For optimal flash reduction we recommend 14.5 or longer barreled host weapons. Extreme durability, low concussion, flash and recoil reduction are the wave of the future- the Flash Comp provides an elegant solution to a complex problem. Includes shim set and over-travel stop washer (for mounting to suppressor).