Glossary
An independent accuracy certification, most commonly from COSC, awarded to individual movements that pass a multi-position, multi-temperature timing test.
Chronometer certification applies to the movement, not the finished watch, and is usually marked on the movement or dial, for example as "Chronometer" or "Officially Certified." A watch claiming chronometer status without the corresponding marking, or with timing performance far outside chronometer tolerance, is inconsistent with a genuine certified example.
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