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Watch news and tools for
collectors and the curious.

Accuracy

How many seconds a day your watch gains or loses, heard through your phone’s microphone.

Jacob & Co. Astronomia Tourbillon Black Gold AT100.31.AC.SD.A
Jacob & Co. · AT100.31.AC.SD.A

Astronomia Tourbillon Black Gold

Change

Somewhere quiet, lay the watch caseback up on something soft. Rest the bottom edge of your phone on the caseback and keep both still.