It is suitable for ac 50/60Hz, which can be used for long-distance receiving and breaking circuit, frequent starting, controlling AC motor, etc. It can also be assembled into building block auxiliary contact, air delay head, mechanical interlocking delay, reversible, star triangle starter, and also can be connected with thermal relay to form electromagnetic starter. Flame retardant housing, copper silver point, copper coil,. A normally open and normally closed auxiliary contact is built into the contactor, and a universal additional module for the whole system can be added. The panel is equipped with dust cover.