GMT function
Displays the time in another zone, usually with an additional hand making one revolution every 24 hours. Local-time adjustment depends on the movement.
Watch glossary
Short definitions for reading specification tables and understanding differences between functions.
Chronograph
Measures an elapsed interval independently of the regular time display, usually with start, stop and reset pushers and dedicated counters.
Chronometer
A designation associated with accuracy tests of a movement or watch under a specified certification system. It does not imply a chronograph function.
Self-winding
A mechanical movement whose spring is wound by an internal rotor as the wrist moves. Infrequent wear may not keep it fully wound.
Power reserve
Approximate running time after the movement is fully wound, before it needs winding again. Actual performance depends on the movement and watch condition.
Water resistance
A rating declared through manufacturer testing. It alone does not describe all usage conditions or current sealing performance. Follow the reference’s manual, especially after servicing or gasket ageing.
Reference number and serial number
The reference identifies the model or version, while the serial number identifies an individual watch. You do not need to publish your watch’s serial number to find its specifications.
