- 5-7 the working ends are 21 mm long with a .02 mm taper. #5 (D1=0.58 mm / D16=1.2 mm) #7 (D1=0.76 mm / D16=1.2 mm). - Duralite® color rings™ handle: 3/8”/9.5mm diameter that has a gradual taper from the tip to the grip. **For further product information, please contact Chat Support**