For the process of drilling for adjustable shelf holes or line boring construction. Eliminates the need for hardened drill guide bushings and dramatically increases the efficiency of drilling for adjustable holes. Features slide pins for 35mm inset positioning as well as adjustable stops for insets greater than 35mm. Can be used on assembled cabinets and cabinet components. Comes with aluminum drill guide for long life and adjustment screws for hole elevation. Can also be used to drill for dowels in cabinet construction.Note: Designed to be used with self-centering drilling tool, bits sold separately