The AR-10/LR-308 lower receiver vise block securely clamps into your bench vise and fits in to mag-well of the lower receiver of your AR-10 LR308 type rifles. This lower receiver vise block prevent damage or movement during gun-gunsmith repair, assembly, disassembly and cleaning. The lower receiver vise block is double sided design fits ArmaLite® AR-10®, Bushmaster .308, DPMS Panther™ LR-308, and Remington R-25 and most other .308 variants. Made from impact resistant and chemical-resistant polymer.