Hand ToolsProduct Description:Material: Diamond-Size: 0.3mm -2.5mm-Shank diameter: 3/32'' - 2.35mm.-This drill bit made from diamond electroplating.-All working length is diamond coated.-All with 3/32''(2.35mm) mandrel. Can be installed on Clamping range 2.35mm or above of electric rotating tools.such as electric grinder, hanging grinder, engraving machine, Pneumatic engraving penetc-Suitable for use in drill hole on jade, agate,stone, crystal, jewelry, ceramics, glass and semiconductor material etc. Please add some water when drill a hole