The switch has the following functions, derived from overvoltage and undervoltage protection. Double-pole cut-off, braking function, single-pole cut-off. Versions can be combined with overload protection switches for undervoltage and overload protection. Widely used in machine tools, large power tools, gardening machinery, and more. This is a safety switch. Once the device is accidentally turned off, it will not turn on. You must press the green start button to turn it on. Type: AC220V KJD17 4 pins color: black Material: plastic Package Contents: 1 x Electromagnetic Push Button Switch Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3 cm.