Beretta Authentic Parts The Beretta Warrior Muzzle Brake is specifically designed for 9mm Pistols and Carbines.The brake is CNC Machined from Solid Steel, treated and and then coated for durability and easy maintenance. It’s threaded with a standard 1/2×28 pitch US thread (Note: if your gun has an European thread you need to find this item: C5J444).The brake comes in a plastic bag, timing shims can be sourced from any gunsmith supply source.We suggest an experienced gunsmith install the brake and time it just right, however user installation is possible. Please remember to follow all gun safety rules when working on firearms as safety is our first concern. External Dimensions:;1.6×0.6×0.6 in (4,1×1,6×1,6 cm) ; Fits on:Beretta M9A3 PMX; Does not fit APX.