Arisaka MCX Zero Retention Clamp Features The Arisaka Defense MCX Zero Retention Clamp consists of exterior clamps that thread into a special U-bracket which engages the extended upper receiver underneath the handguard. This secures the handguard tightly to the upper receiver across two axis directly addressing the flex that can occur when pressure is applied to the MCX Virtus or Spear LT handguard. Without this clamp that flex can shift a laser or front sight zero by 5 mils or more and the zero does not always return to its original position once the pressure is removed. By locking the handguard down the clamp greatly reduces or even eliminates that shift keeping mounted accessories reliably zeroed. Importantly the U-bracket does not contact the barrel or gas system preserving the free floated nature of the barrel and avoiding any impact on accuracy from the clamp itself. The ZRC clamps are contoured to minimize interference with the user s support hand while gripping the handguard so installation does not change how the rifle handles. CNC machined from 6061-T651 aluminum and finished in a Mil-A-8625 Type III hard coat anodized black the clamp is built to handle hard use without wearing down. Designed for the MCX Virtus in 5.56 and 300 Blackout and the Spear LT in 5.56 7.62x39 and 300 Blackout the Arisaka Zero Retention Clamp is a focused fix for one of the platform s known weak points. Arisaka MCX Zero Retention Clamp Specifications Manufacturer: Arisaka Model: MCX Zero Retention Clamp Color: Black Finish: Anodized Material: 6061-T651 Aluminum Compatible Hosts: Sig Sauer MCX Virtus Spear LT Available At: GrabAGun