You can use this UC-604 USB Generation System Radiator easily and it is powered by USB port. No external power needed， just plug straight into your USB port. Powerful but quiet operation. Low power consumption.                                    Features            USB-powered hot plate<br>Temperature of hot drinks can be maintained at 40 degrees after an hour<br>Includes DC to USB Cable<br>Powered via USB from your PC or Mac<br>Low voltage (5V)<br>No driver installation required<br>Colors may vary<br>Size when opened: 4.72" x 4.72" x 0.79"<br>Cable length: 19.7"<br>                                                                                                Package Includes            1 x UC-604 USB Generation System Radiator White and Blue<br>