Real Avid Aircraft Grade Aluminum Lug-Lok Upper Vise Block. These Receiver Vise Blocks & Reaction Rods made by Real Avid fit into all Mil-Spec uppers using the barrel lugs inside the star chamber for a strong hold that won't damage your firearm. This Real Avid Lug-Lok Rifle Upper Vise Block includes two vise pins that allow you to create multiple working angles. Upgrade your workbench with a Real Avid Lug-Lok AR-15 Upper Vise Block for a safer and simpler gunsmithing experience. Specifications for Real Avid Lug-Lok Upper Vise Block: Manufacturer: Real Avid Color: Silver Condition: New Features of Real Avid Lug-Lok Upper Vise Block: Torque Barrel Nuts and Muzzle Brakes without damaging your upper receiver Precision milled lugs solidly fit into the star chamber Non-marring aircraft-grade aluminum rod Bench vise secures at an optimal angle Exclusive Lock Knob locks into position for a solid foundation Fits .223/5.56 AR15s Vise Pin Retaining Holes Lock Knob Retaining Holes 7075-T6 Aircraft Grade Aluminum Star Chamber Locking Lugs Upper Receiver Lock Knob Alignment Flange 2 Stainless Steel Vise Pins Package Contents: Real Avid Lug-Lok Upper Vise Block Real Avid AVAR15LLVB: Aircraft Grade Aluminum Lug-Lok Upper Vise Block