This switch have the following function that derived from power-off and under voltage protection: 1. Double Pole cut off 2. Brake function with one pole cut off 3. These two versions can be combined with overload protection switch to achieve under voltage and overload protection 4. Widely used in machine tools, large-scale power tools, garden machinery above, belonging to the safety switch, the device not turn on after power off unexpectedly, need to press the green button turn on.