The M4SD Flash Comp optimally combines the functions of three traditionally separate classes of devices- Muzzle Brakes, Tactical Compensators, and Flash Suppressors. The M4SD II 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 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). Over-travel stop tab should be positioned at the bottom of the muzzle device (6 O'clock). FeaturesAmbidextrous QD MountFree of wear prone geometryFlash tines help mitigate excessive flashPrecisely calculated porting ...