Elevate your AR-15 build with the CMMG 55CA9CB AR15 Buffer Tube Castle Nut. This essential component provides stability and reliability for your firearm. Crafted to meet stringent manufacturing standards, CMMG's castle nut ensures a secure fit on buffer tubes, enhancing the overall performance of your AR-15. Its matte black finish complements any customization. Castle Nut for Buffer Tubes Fits AR-15 Matte black finish Experience unmatched quality with CMMG's precision-engineered parts and accessories.