USTOP? USB Hand Warmer Heater Winter Laptop PC Heating Warm MousePad /Cartoon Cute Hand Warmer Mouse Pad (Black Female Penguin) Voltage: 5V & absolute security products warm in seconds later but the temperature will not over 40 centigrade low power: 2.5W , spent 1 KWH in 25 days,save power Length of USB Cable:1.3m cheap price but in good quality,don't miss it