PROOF Research pre-fit carbon barrels for Zermatt Arms TL3/SR3 Origin and RimX actions make it easy to upgrade your rifle or change calibers. Our pre-fit Zermatt Arms shouldered barrels are easy to install. Simply thread it on torque it down double check headspace and head for the range. - Lightweight: Up to 64% lighter than traditional steel barrels of similar contour. - Extreme Temperature Resistance: Improved heat dissipation for cooler and longer lasting barrels. - Unprecedented Durability: Wrapped with high-strength aerospace-grade carbon fiber impregnated with a proprietary matrix resin.