You'll know when it's time to refuel with the Tank Up coffee mug.
After a long night, let it be partying, overtime or catching up on TV, there's nothing like a piping hot cup of coffee to wake you up. Made with heat-sensitive printing, the fuel gauge on the outside of the mug is an indicator of how low on fuel -- or coffee -- you are, signalling you to gas up. Since the design can sense the temperature of the cup's contents, it's also a good indicator of when you need to dump out the old stuff for a fresh cup of Joe. Unfortunately, this geeky Tank Up coffee mug is microwave but not dishwasher safe.