The action range of the two floats of the double float switch is 10 mm. If the demand control range is large, two combinations of float switches can be used, so that there is a large stroke to ensure that the pump does not start frequently. The float switch cannot directly control solenoid valves or high-power relays, AC contactors, etc. A small relay (like HH54P) is needed for the transition. The double float switch can be used to control the liquid level of water tank, swimming pool, sink, aquarium, etc. (drain or water), or to make the upper and lower alarm switch of the liquid level. Normal water intake process activated by the float switch below, and the float switch above stops working. The drain is activated by the float switch above and the lower float switch stops working. The contacts inside are a very high sensitivity reed switch. Feature: The float switch cannot directly control solenoid valves or high-power relays, AC contactors, etc. A small relay (like HH54P) is needed for the transition. The double float switch can be used to control the liquid level of the water tank, swimming pool, sink, aquarium, etc. (drain or water), or to make the upper and lower liquid level alarm switch. The contacts inside consist of a very high sensitivity reed switch. The action range of the two floats of the double float switch is 10 mm. If the demand control range is large, two float switch combinations can be used, so that there is a large stroke to ensure that the pump does not start frequently. Normal water intake process activated by the float switch below, and the float switch above stops working. The drain is activated by the upper float switch and the lower float switch stops working. Specification: Voltage: DC 0~110V Material: 304 Stainless Steel Size (Body Floating Length):( Optional) 100 mm / 3.94 inch 150 mm / 5.91 inch 200 mm / 7.87 inch 250 mm / 9.84 inch List Packages: 1 x Double Ball Float Switch