More info here
"The M4SD K offers users a wide range of mounting options using our variety M4SD mounts and compatible A2 compensators.
https://dsgarms.com/suppressors-grfgam4sdk-w
Unique to Griffin M4SD family suppressors is it's SDQD mounting interface. The SDQD mounting system is one of the fastest on the market and accommodates the A2 nato compensator as well as Griffin's M4SD II series proprietary performance rich muzzle device options"

Willie, this will attach to most 22 caliber Carbines/Rifles/AR Pistols etc threaded barrels with a ½x28 thread pitch. If your firearm does not have an A@ style flash hider already, the supplied one works no issue. Cheers and be safe!

It attaches right o er the top of the included flash hider, and will also attach over the top of a standard A2 flash hider. Which either of these will attach to any gun chambered in 556/223 with a ½x28 threaded barrel, so that's a pretty wide variety of guns that will fit that bill.