has been the subject of many posts over the years.I enjoy the Mystery type watches and when i learned the Pierre Cardin/Tian Harlan connection I couldn't resist grabbing this piece.It reminds me of the Pacman game from years ago .Since each hour has a color you can set it using either edge of the cut out for the minutes.Tian Harlan created over 100 different variations of this piece so i have a ways to go to own each one,cheers
P.S. I use to upper edge,time about 3:20 in the photo