When the water runs out, it gives a warning with LED lighting. When the water in the tank runs out, the LED light will turn red and the motor will stop working. The water motor operates very quietly. It automatically stops working when the water runs out. It has a large water tank, 2.5 liters. It has an active carbon filter. The water motor comes with a USB cable and operates with a 220V-240V socket with a 5W1A adapter. You can add water from the top cover as the water level decreases in the water tank. During cleaning the Automatic Water Bowl, unplug the adapter from the socket. Package Contents: 1 piece of automatic alert cat dog water bowl