The Wolfcraft Dowel Quick Doweling Jig self-centers on boards to make quick, accurate dowel joints. Made of high impact plastic, this jig is capable of edge-to-edge, T, and edge-to-corner joints. The jig comes with 1/4-inch, 5/16-inch, and 3/8-inch diameter pins, and can be used on boards up to 1-1/4-inch thick. Other features include hole guides with hardened steel bushings, and the jig can be adjusted to the required front and back depth.