Fits JÄGER PMC and other Re-Direct Flash Hiders.  Heat-Hardened 7075 Aluminum Construction 3-Thread Adaptor. Fits 0.92 Inch Diameter Ruger 10/22 Bull Barrels. 3 thread dimensions in one fitting: ¾ NPT, 13/16-16 and ¾-16UNF. Connects to barrel with nylon-tipped stainless steel set screws. No machining required to attach this part.