The Air Cooler Ultra (15v) is extremely popular. It runs on just 15 volts and starts cooling your room in just 5 seconds! => Fill it with water once and enjoy up to 8 hours of cooling. => It lowers the temperature by 6-8 degrees, which is just as effective as an AC. => Electricity consumption is minimal. It can be powered via Car Charger, Powerbank, Mobile Adaptor, or Laptop charging port. => Turn on this air cooler and sleep comfortably at night without any of the hassle of an AC.