Holland's Muzzle Brake QD 9/16" 28tpi Blued or Stainless Steel 9/16", .580 - .650 tapered. Our triple baffle quick discharge muzzle brake sets the standards by which other brakes are judged. We've probably designed the best brake for your shooting needs. The triple baffle design gives fantastic recoil reduction, a measured 42 to 45% with reduced blast and noise. The blank area on the bottom keeps dust and debris from blowing up around the shooter. The brake adds 1.250" to your rifle's length. The large ports allow for easier cleaning in the field, a must for varmint shooters. Sizes available for barrels .525 to 1.250" . This muzzle brake allows you to see the bullet impact in most all varmint calibers. Please specify in comment section stainless or blued. Check with us for installation usually takes between 5 to 7 days. To order your brake, measure the outer diameter of your barrel and match it to the diameter listed. All muzzle brake exit diameters must be opened up to .020" more than your particular caliber.