PACKAGE CONTAINS:1 Water level controller unit, 3 Sensors, WORKING : On controller auto mode by its switch,As shown in the above diagram out of three sensors, 1 sensor put at the bottom, 1 sensor put at middle, and 1 sensor at top level of the tank. When the water level in the tank becomes low, means water get down from middle sensor, motor get switch on automatically. The tank starts filling up. When the water level reaches to the higher level, the top level sensor sense. the motor automatically gets switched off.No Man power is required. See diagram above in picture for connections. We have tested our product and all our product passes through all necessary test before sell. Applications : Applicable to under ground tank, over head tank, pressure pump, tube well and deep boring. Automatic water level controller is of much used in homes, hospital, industries. Use of this product saves water, saves electricity and save times. Helps in preventing overflow of water from the overhead tank.