Primary Weapons Systems FRC Compensator, 223 Remington/556NATO, Suppressor Mount, Black, Fits 1/2X28 1Q0052 Primary Weapons Systems was formed by firearm enthusiasts in 2008. Starting out by producing muzzle devices" we tested our compensators on all different types of rifles - from M4s to AK-47s. After using both styles of rifles in testing with high round counts" the difference in maintenance needed was both astounding. From that basic realization" the PWS long-stroke piston system was born; keeping the core values of the AR-15 design" while also lessening the need for maintenance in high-volume fire situations and adverse conditions. The new FRC Compensator from PWS mitigates recoil and allows the quick and direct attachment of PWS suppressors.