Power Source : CHARGE Voltage : 110-240V Origin : Mainland China Product Name: Kamoer Auto Top Off Aquarium Water Refill with Anti-Overflow Sensor and Optional S3 Sensor aquarium supply The Kamoer ATO One is a smart water replenishing device that requires only the sensor and the refill pump to be installed. It can be used after power-on without setting any parameters. Includes 1 optical level sensor and 1 float level sensor. The optical level sensor is used to monitor the water level to determine whether water needs to be replenished. The float level sensor is used to prevent overflow. An optional float level sensor is available to monitor the freshwater reservoir for water shortage. The ATO One is rich in status indicators. When the Anti-overflow Sensor or overtime, the refill pump is not inserted or the freshwater reservoir is short of water, the ATO One will have an indicator light and a buzzer alarm. What's in the box? 1x ATO One controller 1x S1 Float sensor 1x S2 Optical sensor