Real Avid AV1015SFVB Smart-Fit Vice Block Reversible Gray/Red Rubber Overmold & Steel Side Fits Master Gun Vise

The most versatile vise block available today. Works equally as well with AR10A and AR15 style firearms. AR10 sleeve slides and locks onto AR15 block for instant flexibility. Expand block to snug fit in just a few turns. Comes with AR Pivot Lock (for AR15) to secure upper for cleaning