The Arisaka Zero Retention Clamp (ZRC) is designed to reduce zero shift for lasers and iron sights mounted on the handguard of Sig MCX Virtus and Spear LT rifles. This innovative clamp secures the handguard tightly to the upper receiver, preventing flex that can lead to significant zero changes. Designed specifically for the MCX Virtus chambered in 5.56 and 300BLK, and the Spear LT in 5.56, 7.62x39, and 300BLK, the ZRC ensures reliable performance without contacting the barrel or gas system, thus preserving the free-floated barrel. Crafted from CNC machined 6061-T651 aluminum and finished with a Mil-A-8625 Type III hard coat anodization, this clamp is built to last and made in the USA.