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. It can be easily converted from normally open to normally close by inverting the float. 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. Product Name: Water Level Sensor; Contacts: NO+NC; Max Contact Rating: 10W Max Switching Voltage: 100V DC; Max Switching Current: 0.5A; Max Breakdown Voltage: 220V DC; Max Carry Current: 1.0A Max Contact Resistance: 100m; Temperature Rating: -30 - +125 C; Float Ball Size(): 25 x 27mm / 1 inch x 1.1 inch(L x D); Thread Dia(): 9.8mm / 0.386 inch Hex Nut Size(): 19mm / 0.75 inch; Bottom Clip Dia(): 15mm / 0.6 inch; Body Total Length(): 81mm / 3.2 inch; Body Total Width(): 70mm / 2.8 inch Cable Length: 31cm / 12.2 inch; Color: Silver Tone; Material: Stainless steel Net Weight: 235g; Package content: 5 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.