Short Answer

Omega does not make a 45mm Globemaster. The Constellation Globemaster ships in 39mm. The Globemaster Annual Calendar ships in 41mm. A listing that says 45mm is mislabeled, measured with the crown included, or built on a case that copies no real reference.

Genuine Globemaster Sizes

  • Globemaster 39mm. Steel, two-tone, Sedna gold, and full gold versions. Calibre 8900 or 8901.
  • Globemaster Annual Calendar 41mm. Calibre 8922. Month and date windows at 12 and 6.
  • Bezel. Fluted, tungsten carbide on steel references. Gold references use gold.
  • Dial. Pie-pan shape with a raised center and applied markers.
  • Magnetism. 15,000 gauss rating on Master Chronometer versions.

Why 45mm Listings Appear

Three causes cover most cases. A seller measures the case from crown guard to crown guard, which adds 3mm to 5mm to the real number. A seller copies the diameter from a different model page. A seller uses an oversized case because a larger movement or spacer fits inside it.

How to Read a Listing

  • Case diameter. Ask for a caliper photo taken across the case without the crown.
  • Lug-to-lug. This number decides fit. A 45mm case with long lugs wears larger than the diameter suggests.
  • Thickness. Compare the seller's photo against the thickness Omega lists for the 39mm and 41mm references.
  • Movement. Genuine Globemaster watches use the Calibre 8900 family with a co-axial escapement and a silicon balance spring. Ask for a photo of the movement and the rotor text.
  • Bezel material. Tungsten carbide looks gray and holds a sharp edge. Plated bezels show wear at the corners.

Certification Text

Master Chronometer status comes from METAS testing of each finished watch. The test covers eight criteria, including rate in six positions and exposure to 15,000 gauss. No replica carries that certification. A case back or rotor that prints the words copies text only.

Fit Notes

A 45mm case is 6mm wider than the genuine 39mm. Measure your wrist width across the flat, then compare it against the lug-to-lug figure. If lug-to-lug exceeds your wrist width, the lugs will overhang.

Weight and Materials

Omega does not publish weights for every Globemaster reference. Treat any gram figure in a listing as unverified unless the seller shows a scale photo.

Legal Note

A replica copies a protected design. Sale and import of counterfeit watches is illegal in the United States and the European Union. The Federation of the Swiss Watch Industry tracks seizures and publishes the totals.