Keep coffee/ tea/ beverage warm at 50-60?? and enjoy the E-communication at the same time.Expand your existing USB port easily.USB Hub and USB full speed.Plug and play with USB interface.4 Ports with automatic recognition function， compatible with all common operation systems.Connect with Max. 127 devices simultaneously.Overload protection for every port.Supply till 500mA through USB port， sufficient for diverse apparatus.Operation system: Windows98/ 2000/ ME/ XP.IMac， G3， G4 or iBook with free USB port.IBM PC 48DX4-100 Mhz or above.Simple plug and play installation， no driver needed.Power: 2.5W 5V DC.On and off switch.Red warmer LED indicator.Powered by USB port， no battery required.High quality insulating material around the Metal-Warm holder plate protection against burning.The temperature will decrease when other USB ports are used at the same time.Size: 10.5cm x 9.5cm x 2.2cm - 4.13inch x 3.74inch x 0.87inch??approx). Notice:Temperature will be reduced if sharing with other USB device.Don?t touch the plate directly when is in use.Unplug the USB cable before cleaning the warmer.Packet include1 x USB coffee warmer pad