Always be prepared and gear up with the best tools you need for your firearms with Real Avid Gun Tools & Gun Maintenance equipment. Work smarter and not harder with the Real Avid Smart-Fit AR-15 Vise Block. This AR-15 Vise Block will take the wobble out of your AR-15 Lower build and allow you to work on a solid foundation. This Vise Block adjusts to fit every AR-15 Magazine Well out there. Insert the block into the magazine well and simply rotate the adjustment handle to tighten the fit. This block can also be used with an inverted lower receiver to work on pistol grips or allow easy access to the underside of your AR-15. This tool also includes a Pivot Lock that holds the gun open giving you access to the chamber and barrel for easy cleaning.