low-voltage semi-automatic electric screwdriver 2)3C ... + power Supply of Frequency Conversion and Stabilized Voltage = Utility and More DurableThe full constituent part ... and output (20-30V) ,frequency conversion & constant voltage ,more stable torque force, temperature and rev.The combination ... of screwdriver:Scope of application:Auto parts,lamps,office equipments,air condition equipments,game machines. ...