Creates joints 50\% stronger than standard Kreg joints. Optimized for large outdoor projects. Stop Block provides easy, repeatable registration to work piece. Face clamp locks into Kreg Jig HD for secure drilling. Hex-shank HD drill bit is quick-change compatible. 1-7/16" drill guide spacings. Works with the Kreg Jig K3, K4, K4MS, and K5.