Self-Centering Doweling Jig (Extra 6,8,10mm Metric Bushings)
This Doweling Jig automatically centers itself on round, square or irregular shapes. Handles stock 10~50mm thick with drill-hole sizes: 1/4", 5/16" , 3/8", 7/16" and 1/2".
Extra eight hardened steel bushings are provided: 2 each of 6mm, 8mm, 10mm to fit most wooden dowels. You can drill two identical parallel holes without moving the jig.
Please note, you will have to measure and mark the positions of the holes manually for this jig.