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 by inverting the float. Note: because the current 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" x 1.1"(L*D); Thread Dia() : 9.8mm / 0.386" Hex Nut Size() : 19mm / 0.75"; Bottom Clip Dia() : 15mm / 0.6"; Body Length() : 81mm / 3.2"; Body Width() : 70mm / 2.8" Cable Length : 31cm / 12.2"; Color : Silver Tone; Material: Stainless steel Net Weight : 47g; Package Content : 1 x Water Level Sensor Note:Light and different displays may cause the color of the item in the a little different from the real thing.The measurement allowed error is +/-1-3 cm.