2 ms·
These were very common in the last century and many continue to be used today: https://en.wikipedia.org/wiki/Telechron https://en.wikipedia.org/wiki/Telechron
by userbinator 2y ago
These were very common in the last century and many continue to be used today: https://en.wikipedia.org/wiki/Telechron https://en.wikipedia.org/wiki/Telechron