The Kaw Valley Precision Plan B Taper Mount Brake is seamlessly engineered to be fully compatible with Plan B mounting systems. Designed to effortlessly attach and detach from your firearm, our brake ensures quick and hassle-free adjustments to your shooting setup without the need for timing or shims. Product Features 17-4 Stainless Steel Material Black Nitride QPQ Finish Shoulder: Square Product Specifications Weight: 1.4 oz OAL: 1.27 Bore: .500 (ANY Caliber)