This is a Gemtech Adapter known as the 1/2X28 W/Thread Protector chambered in 22 LR, model 12205.
GEMTECH again makes the pieces fit: This Adapter will allow you to mount most any suppressor or muzzle accessory using 1/2-28 U.S. standard threading onto the SIG SAUER or German Sport Guns .22lr 1911 handguns. The GEMTECH .22 1911 adapter is precision made to ensure alignment to avoid dangerous baffle strikes.
Features:
This item is not compatible with the COLT/UMAREX 1911/22. That pistol requires the Walther P22 adapter.
