This is a Tactical Solutions Part known as the Compensator, model PLCMP-02.
The Pac-Lite(R) Compensators are a simple addition to spruce up any 1/2"x28 .22LR pistol or rifle. With 360 degree ports" Tactical Solutions compensators help reduce muzzle rise on your barrel.
Features:
1/2X28 thread pitch
Helps reduce muzzle rise
