Temp Control, W77 x H35mm, 3 digit display,3CH input(NTC)[Inlet Temperature + Defrost Temperature + Outlet Temperature or Digital Input(DI)], Compressor + Defrost or Auxiliary(Alarm/Evaporator-Fan)output, Compressor 5A 1a Contact, Synchronize Defrost, 24VAC 50/60Hz, 12-24VDC