"Fake Globemaster 525.10" is what people type when they are hunting a replica of Omega's Globemaster Annual Calendar. Here is the short answer. The 525.10 block is only part of Omega's reference string, and any replica built around it will look convincing across a table but fail on the parts that matter: the month hand, the calendar change at month end, and the movement behind the dial. Judge a watch on those three things and you skip most of the junk.
What 525.10 actually refers to
Omega reference numbers run in blocks. The opening digits carry the family and the case metal. The digits after that name the dial, the bezel and the bracelet or strap. That is why complete references look like 130.30.39.21.03.001 instead of five digits on their own. A seller quoting "525.10" as a full reference is usually working from a photo caption. Pull the whole number from Omega's product page before you compare anything.
The Globemaster itself is easy to describe. 39mm case, pie-pan dial with the angled inner ring, fluted bezel, and on the Annual Calendar version a fourth hand that sweeps around a ring of months. The genuine watch runs a calibre certified as a Master Chronometer by METAS. That certification is where replicas stop being close.
Where a replica shows its hand
Dial and pie-pan
Look at the step where the flat centre meets the angled outer ring. On a good replica that edge is crisp and sits at the same height all the way round. On a cheap one it is soft, and the printed minute track drifts closer to the edge on one side. Applied hour markers should sit flat and catch the light the same way. Check the Globemaster text under 12. Font weight is the giveaway, thin and fuzzy versus sharp and a touch heavier.
Month hand and calendar
This is the one I test first. Set the watch to a month end and watch what happens. A genuine annual calendar goes from 30 to 1 with no input. Most replicas either flip on the 31st like an ordinary date or need the crown. The month hand also tends to be painted rather than blued or polished, and it often sits too high above the dial.
Case and bezel
Fluting should be even and sharp enough to bite light. Polished bevels on the lugs should run the full length without a wobble. Run a fingernail along the join between the bezel and the case. It should catch, not slide.
Checks I run before paying
- Set the month hand to the wrong month, then advance the crown. It should move without grit.
- Set the date to 30 and see what it does on a 30-day month.
- Look at the caseback engraving under a loupe. Soft edges and shallow relief mean a cheap stamp.
- Check the crystal from a low angle. Genuine anti-reflective coating kills most reflections. Cheap coating leaves a blue or purple haze.
- Weigh it. Replicas often run light, mostly because of the bracelet.
- Ask for movement photos. Any honest seller has them.
What no replica gets right
METAS tests each certified movement for accuracy and for resistance to a 15,000 gauss magnetic field. No replica factory reproduces that testing or the paperwork that comes with it. Service is the other wall. Omega will not touch a replica, and many independent watchmakers refuse annual calendar modules because parts are hard to source.
Worth saying plainly too: a replica is not an investment, and you cannot legally sell it as a genuine watch. Buy one because you like the look on your wrist, not because you expect it to hold value.