1、The float switch cannot directly control solenoid valves or high-power relays, AC contactors, etc. A small relay (such as HH54P) is needed for transition. 2、The double float switch can be used to monitor the liquid level of water tanks, swimming pools, sinks, fish tanks, etc. (drain or water), or to act as an upper and lower liquid level alarm switch. 3、The contacts inside are made of reed switches with very high sensitivity. 4、The operating range of the two floats of the double float switch is 10mm. If the required control range is large, two float switch combinations can be used to ensure a large stroke to ensure the pump does not start frequently. 5、The normal water inlet process is activated by the lower float switch, and the upper float switch stops working. The drain is activated by the top float switch and the bottom float switch stops working.