Real Avid Master Bench Block, Rubber/Plastic Material, Red/ Grey Finish, Bench Block for AR Style Rifles AVAR15MBB The most comprehensive AR15 bench block ever allows you to tap 13 critical pins from 5 different components. The block is wrapped in an over-molding that grips to your bench to prevent slippage. Plus" engraved on the ultra-tough engineering grade surface are clear component labels marked with pin punch sizes to make determining what component to place where and what pins to use" simple. On the backside of the block" to capture pins and keep them from rolling away" are embedded magnets and" to keep your pins from getting lost" a pin storage section is included.