The AR15 Master Bench Block holds 5 key AR15 components in 8 different orientations to allow you to knock out and install up to 13 different pins. The block is wrapped in over-molding that grips your bench so it won't slide around. Clear, engraved labels tell you what component fits where, and what size punch you'll need to knock out the pins. The biggest innovation is mounted inside - four strong magnets immediately grasp any pin you punch out and hold it securely to the block. It even includes storage for common size pins. This is a bench block you can swear by.Specifications and Features: Lower Receiver fits for trigger assembly pin removal Gas Block fits in two orientations for installing and removing pins T-Handle compresses ejector to easily remove ejector pin Pin storage keeps common sized pins within reach Ambidextrous charging handle feature makes latch or spring replacement quick and easy Upper Receiver cavity compresses forward assist plunger for easy removal and installation Lockable vertical stand for lower receiver provides convenient access to bolt catch Bolt face cut-out holds bolt vertically to simplify gas ring installation