Dowel jig self-centering - Blackjack 16227

The self-centering feature of this jig puts the holes exactly in the center of the board. The convenient positioning marks allow you to align it easily -board to board. Two permanent holes guide 7/16" and 1/2" drill bits. Removable 1/4" 5/16" and 3/8" bushings are interchangeable in 2 other threaded holes in the guide. Hardened guides for long life. Accommodates wood up to 2" thick. Click here to see a great article... "Troubleshooting dowel-joint problems" by Canadian Home Workshop