The Patent Pending Arisaka Zero Retention Clamp (ZRC) greatly reduces zero shift for lasers and iron sights that are mounted on the handguard of the MCX Virtus and Spear LT. This version is designed for the MCX Virtus chambered in 5.56 and 300BLK, and the Spear LT chambered in 5.56, 7.62x39, and 300BLK.