Excalibur Electronic USB Travel Mug Black 494 EXCALIBUR 494 Electronic USB Travel Mug Black. While studying and entertaining on the computer, many of us often have a cup of coffee or soup on our desk. The problem is that time seems to move so swiftly when browsing the web. This cup can use the power from one of the USB ports to keep the liquid warm. What a great idea It even has a 12V car adapter to keep beverages warm in the car. This Excalibur 494 Electronic USB Travel Mug fits most drink holders. This mug holds 16 ounces of your favorite beverage or Soup etc. and keeps your beverages the perfect temperature on the go. Take it anywhere you go and your contents are safe because the Excalibur mug has a convenient spillproof lid. Rubberized handle makes for a comfortable hold. Works with both PC and Macintosh computers and is USB ready. Double stainlesssteel construction.