A contactor is an electrically controlled switch used for switching an electrical power circuit, similar to a relay except with higher current ratings and a few other differences.Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal. A type of relay that can handle the high power required to directly control an electric motor or other loads is called a contactor. SKU: 3UA55002C Product Features: 16 – 25A SICOP BIMETAL-OVERLOAD RELAY CM FOR 3TF34/35;44/45