The Wheeler Engineering Delta Series AR-15 Upper Vice Block Clamp allows you to safely clamp the upper receiver in a vice without twisting, crushing or marring the finish and fits left- and right-hand MIL-SPEC A2 upper receivers and flattop receivers. Includes a receiver insert with a gas tube aligner. Wheeler Engineering Delta Series AR-15 Upper Vice Block Clamp - Shooting Supplies And Accessories at Academy Sports