Specification: Origin: Mainland China Type: Module Condition: New Working Voltage: DC 12-15V(AC 9-12V) Standby Current: 10ma Working Current: 40ma Size: 55.00x27.00x19.00mm/2.17x1.06x0.75inch Weight: 22g Interface Description: HIGH: High limit probe OUT: Output probe LOW: Lower limit probe IN+: Power terminal 1 (positive and negative polarity are not distinguished) IN-: Power terminal 2 (no positive or negative polarity) NC: Normally closed relay contact COM: Normally open relay contacts NO: Normally open relay contact Working Principle: Water Level Rise: when the water level is lower than the "low water level", the pump starts to supply water to the water tower; when the water level is higher than the "high level", the pump stops supplying water. Water Level Lower: when the water level is lower than the "high level", the pump does not work, the water level continues to decrease. When the water level is lower than the "low level", the pump starts to supply water to the water tower. Application: Household water tower automatic water supply system, aquarium fish tank water change system, conductive liquid automatic control, livestock automatic feeding system, farm automatic water supply system and other occasions that require automatic water supply and water change. Note: The package does not include the probe (wire). There is no need to use a special probe, the probe can be made from household wires. For safety reasons, please use a well-isolated AC/DC power supply. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviation due to manual measurement. Included: 1*High Power Water Level Automatic Controller 1.Automatic Water Level Control: Achieve automatic control of water levels with this high power water level automatic controller, allowing you to maintain the desired water level range by regulating the operation of pumps, valves, or other devices. 2.Precise Control Capability: Equipped with precise control algorithms and feedback mechanisms, this liquid sensor switch control relay board ensures accurate control operations based on real-time water level data. 3.Interference Resistance: Designed with excellent interference resistance, this automatic water supply controller module can reliably operate in various environmental conditions. 4.Enhanced Safety Protection: This solenoid valve water pump motor switch includes essential safety protection features such as undervoltage protection and overcurrent protection to ensure the safe operation of equipment and systems. 5.Multiple Sensor Compatibility: Compatible with various water level sensors including float switches and electrode sensors, this water level detection sensor module supports a wide range of sensor options.