If you"re adding shelf pin holes to an existing piece of furniture or building shelves from scratch, the Kreg Shelf Pin Jig is the perfect tool for the job. Unlike other shelf pin guides, the Shelf Pin Jig features hardened steel drill guides which ensure perfectly precise and straight drilling, a dual position adjustable fence for custom hole placement, an included locating pin for quick and accurate spacing reference, a handy jig extender which lets you connect multiple Shelf Pin Jigs together for high-speed production work, and features a handy and secure storage space for the drill bit and locating pin built right in to the back-side of the jig.