Looking as though it could be the latest techno-piece for James Bond, the Kisai Tenmetsu watch tells time not with minute, second and hour hands, or even digitally, but with a series of OLED-based flashing buttons.
The Kisai Tenmetsu wristwatch is made of aluminum and its face contains 10 buttons which contain three colors. When each individual LED is lit up, it tells the time (24 hour format, i.e., 1:30pm would be 13:30), date, month and year.
Your brain will definitely get a daily dose of basic math skills because you have to add or multiply units to get the time. Red represents 15 units, amber 5 units, and green 1 unit.
Thank goodness Tokyoflash has an interactive instruction manual for the Kisai Tenmetsu watch on their website because the concept is a bit hard to grasp from the front page description.