Yankee Hill Machine sRx Mini Muzzle Brake OD Black Phosphate Steel 1/2-28 tpi 9mm. This Q.D Muzzle Brake's compatible Q.D. Adapter/Mounting Interface attaches to the industry standard (HUB) 1-3/8 x 24 threads. It features an internal taper seal-in front of the threads-that locks your suppressor on and forms a tight seal to contain gasses while in-use. This means no gasses or debris can build up on the threads. The sRx Mini Muzzle Brake must be paired with The YHM sRx Adapter (YHM-4400). The sRx Mini Muzzle Brake adds minimal length and weight to the suppressor set up while also allowing you to reap all the benefits of the YHM sRx System-when used in conjunction with The sRx Adapter. The full YHM sRx (Suppressor Rx) System will be the obvious choice for someone looking for a sleek low-profile suppressor set up-thats also built to withstand rigorous use. This is the prescription for the shooter who cares about the aesthetics of their build as well as its ease-of-use. Specifications for Yankee Hill Machine sRx Mini Muzzle Brake: Manufacturer: Yankee Hill Machine Color: Black Caliber: 9mm Luger Finish: Phosphate Fabric/Material: Steel Length: 1.1 in Weight: 1.4 oz Condition: New Features of Yankee Hill Machine sRx Mini Muzzle Brake Timeless. (No need to shim/time to barrel) Small/low profile No moving parts Large taper in front of the threads allows for consistent mounting. Lighter than many Q.D. mounting offerings on the market Can be permanently attached to firearm barrel needed Package Contents: Yankee Hill Machine sRx Mini Muzzle Brake Yankee Hill Machine 4401MB28: sRx Mini Muzzle Brake OD Black Phosphate Steel 1/2-28 tpi 9mm