The Magpul MAG536 BEV Block is an indispensable tool for any work that requires clamping of the AR15/M4 upper or lower receivers.
Clamps in a vise for a solid work area. Inserts into barrel extension with steel lugs to hold upper receiver solid when tightening barrel nuts, flash hiders, and other attachments. Included pin keeps upper in proper position.
Also serves as a mag well vise block for ease of work on lower receivers.
Made in U.S.A.