... efficient 3.Positional accuracy is hig. Ultrasonic Drilling and Carving Machine Voltage:220VPower:2.5KWWorking frequency:15kHz ... , overcurrent, overvoltage, automatic protection 3, large power, efficient and save energy, no radiation, no pollution 5, suitable for ... processing jades, crystals, agates, glasses, hard alloys and all kinds of semi-precious stones and metals with higher hardness