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Mass-produced#1 in familyOfficial press photos

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Mid-tier supplier movement · caliber Oris Cal. 690: ETA 2836-2 base, automatic second-time-zone, 28,800bph, 38h PR; dual-time subsidiary dial; used in Big Crown Worldtimer; Oris second-time-zone complication · 38h power reserve
Large case: suits wrists 7 in+ (18 cm+)
45 mm case. A bold, statement-size wear. Best suited to larger wrists where the case sits flush.

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Authentication

City name disc legibility and 1-hour GMT increment function are the two auth checks.

Known issues in the market
  • City name disc printing can rub if cleaned incorrectly; all 24 cities must be legible.
  • Cal. 690 worldtimer mechanism must advance cleanly in 1-hour increments.
AreaWhat to checkWhat is correctRed flag
dialCity name disc legibilityAll 24 city names legible; no rubbing, smearing, or missing textAny city name rubbed, smeared, or unreadable; disc cleaned with abrasive
movementWorldtimer 1-hour advancementCity disc advances cleanly in 1-hour increments via crownNon-incremental advancement; disc slips or fails to advance correctly
casebackCal. 690 designationOris Cal. 690 in-house worldtimer caliber designationNon-Oris worldtimer caliber; Cal. 690 designation absent
Common legitimate replacements
  • Leather strap; Oris OEM preferred.
  • Crystal; anti-reflective sapphire standard.
Expert resources: Oris Big Crown Worldtimer press materials. Oris Cal. 690 worldtimer documentation.

Authentication guide

Last reviewed June 2026

Oris Big Crown WorldTimer (ref. 01.690.7754.4051), Cal. 690 in-house worldtimer movement. Displays 24 cities on the bezel ring and references them against a 24-hour inner ring. The rotating city disc and 24-hour display are the authentication anchors.

Known reproduction risks

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LOW

A functioning worldtimer complication is extremely difficult to reproduce at low cost. The primary risk is a non-functioning display piece.

  • City disc that is decorative only and does not rotate
  • Inner 24-hour ring that does not advance with the hour hand
  • City names printed on a flat disc rather than applied or engraved

Test the crown-operated city disc advance before purchase. It should click cleanly in one-hour increments.

Dial variants by era

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EraDescriptionIdentifiers
2019 to presentCurrent production. Worldtimer disc displays 24 cities; city names rotate with the bezel. Inner 24-hour ring shows AM/PM. Date window at 6.
  • City disc bezel with 24 named cities in standard IATA time zone groupings
  • 24-hour inner ring on the dial (non-rotating)
  • Date at 6 o'clock
  • Oversized Oris crown for city disc adjustment
  • "Big Crown WorldTimer" printed on the dial

Service part flags

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City Disc / Bezel

Original: Rotating city disc bezel with 24 international cities. The disc is part of the Cal. 690 worldtimer complication.

Replacement tells
  • Non-rotating bezel where the worldtimer disc should rotate
  • Missing city names or incorrect city listing
  • City disc that does not advance correctly in 1-hour increments via the crown
Movement (Cal. 690)

Original: In-house Cal. 690 worldtimer. 42-hour power reserve. The worldtimer module is built into the movement architecture.

Replacement tells
  • Worldtimer disc not synchronized with the movement (showing incorrect time zone offset)
  • Movement visible through display caseback without the worldtimer module plate layer

Case back markings

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2019 to present
  • "ORIS CALIBRE 690" on caseback or rotor
  • "WORLDTIMER" designation
  • Reference and serial number
  • "SWISS MADE"
  • Display caseback (standard on most WorldTimer variants)

Movement tells

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  • Cal. 690 is an in-house worldtimer. The movement architecture includes the worldtimer module as an integral component; it is not a bolt-on module over a standard base. Service should only be performed by Oris-authorized centers.
  • Power reserve is 42 hours. A movement claiming Cal. 690 with a different power reserve is incorrect.
  • 28,800 bph beat rate.
Sources: Oris official — Big Crown WorldTimer.

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