Cup Warmer Heater with Clock has four foam rubber feet to keep it firmly and securely on your desktop * LED red status light and ON/OFF warmer switch; Main Function: Warming plate for ceramic, glass and metal cups/mugs * Power: USB port of computer; Heating Plate Temperature: standard operation up to 60 (celcius); Systems: Windows 98SE / Me / 2000 / XP / Vista * Power Source: Computer USB for warming plate and hub, button battery for clock; Energy Usage: approx 2.5W * Package Contents:1 x USB Cup Warmer; 1 x Instruction Sheet(English Chinese)