USB Powered Beverage Coffee Warmer with 4 Port USB Hub Easy installation, no driver required, plug & play. Keep beverage, coffee or tea warm at 113- 122 degrees Fahrenheit (45-50 degrees C). Rated power: 2.5W - 5V DC Red LED indication when warmer is turned on. Green LED indication when warmer is plugged in to USB. USB powered, no batteries needed. Four USB ports so you can power multiple USB device On, Off switch. Quality insulation material around the metal hot plate prevents burns Works with Mac and PC. Conveniently sized to fit in your laptop bag. Great for travel. Dimensions: 3.625 x 4.125 x .875 inches. USB cord length: 37.5 inches.