American Precision Arms Micro Bastard Gen 1 Muzzle Brake 9/16x32. While it may appear small in size this brake doesn't know it's small. they use this brake exclusively on their Critter Get'r rifles chambered up to a 338 Ultra mag with great success. There simply isn't another brake of this size on the market today that will outperform this brake. All required installation by a competent gunsmith. By properly fitting this brake you can achieve a perfect seamless fit on your rifle as well as perfect coaxial bore alignment. Please see the video for further information. Specifications for American Precision Arms Micro Bastard Muzzle Brake: Manufacturer: American Precision Arms Color: Stainless Finish: Plain Fabric/Material: Stainless Steel Threads per Inch: 9/16x24 Model Generation: 1 Inner Diameter: 0.75 in Outer Diameter: 0.75 in Weight: 1.6 oz Package Contents: American Precision Arms Micro Bastard Muzzle Brake American Precision Arms G1M196GSS: Micro Bastard Gen 1 Muzzle Brake 9/16x32