Woodstock D4116 Doweling Jig Handles stock up to 2-Inch thick Drill-hole sizes are 1/4-Inch, 5/16-Inch, 3/8-Inch, 7/16-Inch and 1/2-Inch Six hardened steel bushings are provided; Two each of 1/4-Inch, 5/16-Inch and 3/8-Inch