Water cooling------The cool breeze is for you. You can add ice water to the inner water container and then the fan will blow a cool breeze to moisturize the air while reducing the temperature inside the door and reducing fatigue. Low noise------The cooling fan produces low noise when working providing you with a quiet and comfortable rest or working environment. Portable design-----The water-cooling fan is small in size easy to place on the desk and bedside and has a small space suitable for use in bedrooms offices and cars. Specification: Type: Water cooling fan Material: ABS PC electronic components Battery voltage and current: 5V/1A Battery capacity: 4000mAh Water tank capacity: 150ml Rated power: 5W Size: 133*111*158mm