欧美日产国产精品-特大巨黑吊xxxx高潮-日韩人妻无码一区二区三区99-国产熟睡乱子伦午夜视频-成 人 免 费 黄 色

The push button switch, also known as the control button, is a low-voltage electrical appliance that is manually and generally automatically reset. The button is usually used to issue a start or stop command in the circuit to control the on and off of the electrical coil current of the electromagnetic starter, contactor, relay, and the like.
The push button switch is a kind of electric device that is used to switch on and off the small current circuit when the action is released. Generally used in control circuits with AC and DC voltages below 440V and currents less than 5A.