ProMag PM123 Lower Vise Block AR-15, M16 Polymer

This vise block allows the user a 'third-hand' to work on and install parts to AR-15/M-16 lower receivers. The vise block is clamped into the users vise and the block is then inserted into the lower-receiver's magazine well and is held in place by the magazine catch. Constructed of a black injection-molded polymer for years of service. Made in the U.S.A.