Calibre 281 — eccentric regulator, centre seconds

In brief

Same 17 jewels as the 280, same 18,000 vph, same centre-seconds layout. The difference sits at the regulator: an eccentric one, fitted so the rate can be brought in more finely.

Short history

It arrives with the 280 out of the renumbering of 1949 that created the 28x series. The eccentric regulator marks it as the precision-minded member of that generation, the role the 262 played over in the sub-seconds branch.

Watches that used it

• Omega dress watches, late 1940s