Abstract: A device for guiding a router bit in the cutting of pins and tails during the formation of dovetail joints, box joints, and other similar types of joints. The device comprises a base which is adapted to be removably combined with a template and may be transparent. The template has a tail side and a pin side. The tail side comprises a plurality of spaced parallel notches adapted to guide a router having an angled tail bit along the workpiece to create the tails. The pin side has a plurality of notches with sides angled such that each notch is wider toward the bottom of the notch (away from the edge of the template).