Pro Mag AR15/M16 Low Receiver Magazine Vise Block 58069. The AR15/M16 Magazine Vise Block from ProMag is a gunsmithing essential that enables you to secure AR15 and M16 lower receivers for maintenance and modifications. This Gunsmithing Equipment from ProMag is made of sturdy polymer that can withstand heat oil solvents and corrosion when working on your firearm. The Pro Mag AR15/M16 Block fits magazine detents of various size holds magazines firmly in place and works with standard blocks. The Pro Mag AR15/M16 Magazine Vise Block allows gunsmiths to hold AR receivers in a magazine vise for adjustments alignment and assembly - all without damaging the device. Specifications for Pro Mag AR15/M16 Low Receiver Magazine Vise Block: Manufacturer: ProMag Gun Model: M16 AR-15 Gun Type: Rifle Fabric/Material: Polymer Color: Black Package Contents: Pro Mag AR15/M16 Low Receiver Magazine Vise Block What firearm models does the manufacturer say Pro Mag AR15/M16 Low Receiver Magazine Vise Block is compatible with? The manufacturer suggests that Pro Mag AR15/M16 Low Receiver Magazine Vise Block is compatible with AR-15 M16Pro Mag 58069: AR15/M16 Low Receiver Magazine Vise Block