... +,B-:Stepping motor other winding5,PUL+,PUL -:Stepping pulse input+5V (Rising edge effective , rising edge duration >10 ... μS)6,DIR +,DIR-:Stepping motor direction input, voltage level touched off,high towards, low reverse7,ENA+,ENA-: motor free ... axle flows fan dispels the heat, to make the module run reliably for a long time.2, Half ... Stepping motor driver,1.3A-4.5A,high quality and reasonable price