Product Features KeyMicro Adapter: Unleash the most secure mounting system for your Wolfman. The KeyMicro Kit includes the KeyMicro adapter, compatible with KeyMicro brakes (included), KeyMicro flash hiders, and Keymo flash hiders. KeyMicro Brake: The included 1/2-28 KeyMicro Brake is bored out for 9mm projectiles. You can mount this on your subgun or 5.56 carbine with no issues. Product Specifications Caliber rating: 9mm, 5.56, 300blk, 7.62 39, 350 legend, .357 mag Energy rating: 2000 ft lbs Bore diameter: 9mm Length (long w/keymicro adapter): 8.75 inches Length (short, w/keymicro adapter): 6.35 inches Diameter: 1.618 inches Weight (long w/keymicro adapter): 19.2 ounces Weight (short, w/keymicro adapter): 13.8 ounces Materials: fully welded 17-4 ph stainless steel Finish: black Usage: extremely tough subgun silencer. We even rated it for carbine use when using the keymicro adapter and mount. Barrel restrictions: none Full auto rated: yes