... Ultrahigh frequency,Double frequency) it is appliying for classes of machine parts to heat treating(quenching,anneal, temper,normalizing..., Through ... of protecting itself when over current,over voltage,lack of water,phase fail,over hot,etc. 3.It has the function ... it is more convenient use. 4.Special cycle cooling system, make sure the machine work 24 hours continuously. For details,please feel ...