USB warmer: 1) Keeps coffee / tea / drink warm at 50-60°C 2) Easy installation, no driver required, plug and play 3) Rated power: 2.5W, 5V DC 4) With on / off switch 5) Red LED indication when warmer is turned on 6) Quality insulation material around the metal hot plate to prevent burn 7) USB powered, no batteries needed System requirement: 1) iMac, G3, G4 or Book with available USB port 2) IBM PC 48D x 4-100MHz or higher 3) OS: Windows 95/SE/ME/2000/XP