Ergo Spikes Block (AR10) 4989This is one of the most useful maintenance accessories available for an AR-10. Simply bolt or clamp securely to a bench or other work surface, place an AR rifle onto the block inside the magazine well and the rifle is held in place for cleaning, maintenance or storage.Features:- 1-piece glass filled polymer design- Fits rifles that use SR-25 pattern magazines- 6-1/8 tall x 2 long (at the base) x 4-1/4 wide (at the base)- 1/4 mounting holes- Weight: 7oz