Since 1999. This useful tool is for accurately mitering corners. Unlike other corner jigs, this one is infinitely adjustable between 20-200 point board thickness for perfection obsessed binders. Super easy to clean Delrin base. Great for one-off binding and essential for high end production work. This jig allows butt joining of cloth, paper, vellum or leather. Perfect corners every time. Instructions for use included. Bronze and Delrin. 6" cutting edge.