Mini USB PC Fridge Beverage Drink Cans Cooler & Warmer Red It works with any computer operating system and does not requires batteries You can keep your beverage cool or warm and stay at your computer longer. Simply plug the USB port in, insert your drink and enjoy. Supports Cooler & Warmer. The LED light turns green when cooler, turns red when warmer. Takes minutes to cool down to 8-10 (46-50) or warm to 40-50 (104-122). Perfect for the office worker.