Redefine stability and simplicity in your AR build. Self-Retention Thread Design – Armaspec’s innovative self-retention castle nut utilizes patented thread locking technology the unique thread delivers improved security by locking in place without the need for staking or thread locker. Designed for quick and easy installation saving you time without compromising performance. Made from premium-grade 7075 aluminum for exceptional strength durability and reduced weight — perfect for high-performance light weight builds.