This is our HC9C 3.0 compensator it was designed for the Glock 19 and 17 that will fit ALL Glock barrels! It is 100 percent reliable with its stock springs, meaning you dont need to change a thing! It is made out of CNC machined 6061 aluminum with either a black Cerakote, FDE Cerakote, or a black anodizing finish. It has a 1/2-28 thread so it will fit any barrel, therefor no expensive proprietary barrel system! If you want a small, reliable, and effective compensator, this is it! It comes with a lifetime, NO questions asked Warranty! 5/64 Allen key included. ALL barrels require rubber O-ring removal to fit flush. We do NOT know every states laws and regulations on threaded barrels or muzzle devices, therefor purchasing our product you take responsibility on weather or not these items are legal in your state. We do not ship to other countries. Two different set screw lengths will be provided for perfect fitment.