I have always wanted to look for The Longines Comet, a short-lived mystery dial from the seventies. It is an unusual watch, featuring a broad arrow for hours and an orbiting dot for minutes. Both are on revolving discs, making them appear to move without being connected to the dial, hence the term 'mystery dial'.
The indication 'T Swiss Made T' on the bottom of the dial means that the watch contains a certain quantity of tritium that emits less than 227 MBq (7,5 mCi). The watch is considered to be uncommon, as the design was deemed too avant-garde for tastes at the time, so comparatively few were sold. Red is the most rare colour, followed by yellow, the most common colour being blue. It was also produced in black and white, and in brown and green variations. I have managed to find the yellow one..cheers
