Well, Beta21 is the first Swiss quartz wristwatch and we have written a lot about this fantastic innovation:
See its story in these four parts:
And see our research results about the numbers made for each brand -- in total 6'000:
These are the number the major participants were produced in between 1970 and 1972. Today this distribution looks completely different, given the fact many of the 2nd row brands were smelted, destroyed or simply got lost -- but thats another story.