Primary Weapons Systems Piston, Fits M13.5X1LH, Anodized Finish, Black

Primary Weapons Systems was formed by firearm enthusiasts in 2008. Starting out by producing muzzle devices, they tested their 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 13.5x1 LH piston allows the use of PWS suppressors on 13.5x1 LH threads. • 13.5x1 LH • Anodized Finish • Black