This is a Mini stainless steel float switch, contains no mercury. This float switch is a device used to sense the level of liquid within a tank, the switch may activate a pump, an indicator, an alarm, or other device. This Mini float switch is a simple structure, easy installation liquid level controller. It does not have a complex circuit, will not be disturbed, as long as the material selection, liquid, pressure or temperature can be used in any environment. Light weight and simple working principle, high reliability. The versatility of this vertically mounted sensor means that it can be installed either at the top or base of your tank, depending on whether you wish to detect the water rise or fall. The float level switch is widely used in electronic, electrical, chemical, water treatment, drainage and other walks of life level control and alarm.