You know the situation, you just filled a nice glass of Cola, and the phone rings. Once you hang up, the once refreshing cool drink is a miserable shadow of its former self, all the coolness is gone. Inevitable? No way! Here's where the USB warmer cooler enters the scene. Just plug the USB warmer cooler into your computer's USB port, simply flip the switch on the back of the best travel coffee mug to alternate between heating and cooling and you can keep your drinks either warm or cool. Many of us enjoy tasty beverages while working on a computer. Keep your beverages the temperature you want with this USB beverage cooler. The USB gadget plugs directly into your computer, so you can keep your coffee hot without having to leave your desk. Plus, the USB coffee warmer also features a built-in fan so you can keep your cooler drinks cold. Finally a way to enjoy your beverages during work hours the way they should be enjoyed, either properly cooled or wonderfully warm. This Coffee cup warmers adopt high precision silicon cooling, no pollution.