low-voltage semi-automatic electric screwdriver 2)3C.UL,ISO9001, 3)One year warranty ... -Japanese motor AS semi-Automatic Electric ScrewdriverLow-voltage DC Motor Brand-new + power Supply of Frequency Conversion and Stabilized Voltage = Utility ... ) ,frequency conversion & constant voltage ,more stable torque force, temperature and rev.The combination of spring crane ,power supply, and electric screw ...