These compensators are specifically designed for the XD/XDM to work with 9mm major ammuntion and a reduced power recoil spring. Anodized 6061 aluminum for a light weight, long lasting compensator to tame muzzle flip and soften recoil. 1/2 x 28 tpi requires .4" to .5" of threads for 9mm. Not for factory threaded barrels. For our Bar-Sto compensator threaded barrels.