USB Water/Coffee/Tea Cup 130 ML Gadgets Warmer/Heater Mug with Automatic stirring - Black In-set Li-ion battery. Use portably. Can recharge repeatly. In-set heating and warming function. Keeps your beverage at comfortable 40'C. Magnetic water. Automatic self stirring function. Compatible with PC hardware USB Port. Voltage: 3-5V, Power: 3W. Nominal Volume: 130 ml (4.4 fl.oz.), Dimension: 62 x 62 x 150 mm.