A float switch is a device used to sense the level of liquid within a tank. The switch may actuate a pump, an indicator, an alarm, or other device. Use them with hydroponics, saltwater tank, freshwater tank, gardening, aquariums for power head control, pet bowls, fish tanks, filtration, heating, pumps, ponds, basement alarms, boats, air condition drain pans, pressure washers, carpet cleaning mach, reef aquarium, fluid control, ice machines, coffee pots, marine, automotive, automobiles, tropical fish tanks, evaporator coils, condensation line, in relays, or what ever your project may be. Note: because the current that the switch can carry is much little(0.5A), you must use a relay or contactor when it is connected by a load, relay and contactor are not included here. Thread Dia: 9.5mm; Wire Length: 39cm/15.35 inch ; Float Ball Size: 55 x 17mm/2.2 inch x 0.67 inch (L x D) Max. Breakdown Voltage: AC/DC 220V; Max. Switch Current: 0.5A; Max. Switch Voltage: AC/DC 100V; Max Wattage: 10W Temperature Range: -30C- +125C; Max. Contact Resistance: 100m Ohm; Hex Head Size: 14 x 14 x 4mm/0.55 inch x 0.55 inch x 0.16 inch (L x W x T) Breaking Height: 94mm/3.7 inch ; Breaking Angle: 45 Degree; Body Total Length: 119mm/4.6 inch ; Product Name: Float Switch Country of Manufacture: CHINA; Material: Stainless Steel; Color: silver Net Weight: 152g; Package content: 4 x Water Level Sensor Only the above package content, other products are not included. Note: Light reflection 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 +/- 1-3cm.