Does your barrel have a tapered muzzle shoulder but you need to use shims for your muzzle brake? Do you use silencers that requires a 90Adeg square shoulder? If you answered "yes" to either of these questions, then head over to Silencers by Q to get that fixed! Can't afford a new silencer? Q has got you covered! Use this Taper Adapter to convert your scientifically engineered 1/2-28, 5/8-24 muzzle, and M18-1.5 into a traditional 90Adeg, non-scientific shoulder. Specifications: Material: 17-4 Stainless Steel Coating: Heat Treat (Color May Vary)