So we often refer to the marking at the bottom of the dial, the SWISS mark.
Beneath the six o’clock marker on all Speedmasters is this mark in three varieties:
- T SWISS T (Close spaced T’s)
- T SWISS T (Wide spaced T’s)
There is another version I have heard of, where the T’s are added later, slightly out of line. (I don’t have an example)
Here is a comparison of the two. (Note the short indices, that stop short of the minute track – but thats another subject)