This is a Tactical Solutions known as the Pac-Lite chambered in 22 LR, model PL4. 5TENF-02.
The Pac-Lite is the original go-to upgrade for tricking out your Ruger(R) Mark I" Mark II" Mark III" and 22/45(R) series pistol. Installation on your existing MK frame is a cinch without the need of a gunsmith. Crafted from a solid piece of aircraft aluminum" the Pac-Lite provides an ultra strong and lightweight experience.
Features:
Threaded Barrel
Drilled and Tapped for Pac-Lite������� Scope Bases
Fully Customizable