SEIWA Hishikiri No. 3 Hand Sewing Hole Punch Marking Tool - Uniform Blade Width Compatible with the blade width of diamond chisels. Because the blade width is uniform, the hole size does not change even when inserted deeply. Hishikiri "no." and Diamond Chisel Compatibility Chart no. 1 = 3mm width diamond chisel no. 2 = 4mm width diamond chisel no. 3 = 5/6mm width diamond chisel How to Use 1. Use a stitching groover or divider to create a groove or guideline. 2. Mark with a stitching roulette. 3. Punch holes one by one, matching the angle of the diamond chisel. *After use, if you apply machine oil or CRC oil and store it, the sharpness will last.