Definition
What does COSC mean?
The Swiss Official Chronometer Testing Institute, known for certifying movement accuracy.
Collector Context
Why it matters
This term helps describe a watch’s construction, function, historical importance or market position. Understanding it makes specifications easier to compare and supports more informed buying decisions.
TimeHunter Insight
Do not judge a watch by terminology alone. Execution, condition, originality and the quality of the underlying movement remain more important than a feature name.