This kind of product is bitable. The contact state is maintained by permanently magnet. Applying a pulse of current to coil can change the state of contacts (either from on to off or from off to on). The energizing time may be less than 1 second. When the coil is reenergized, the contact of contactor will maintain the state of on or off. Each product has two coils with two connecting means: 1. series coils, changing direction of current may realize on and off; 2. one coil realizes pick, the other one realizes release in which two-pole power supply is required. The latching series, integrated with normally open contactor and normally closed one, provides more choices for customers. This kind of product is suitable to programme-controlled power supply and continuous power system. You can visit www.dccontactor.com.cn for more information. Should you have any questions, please feel free to contact us.