The Speedmaster Reduced and the Speedmaster Moonwatch Professional share the Speedmaster look, but they are different watches. The Reduced is a smaller, automatic model commonly identified by reference 3510.50.00; the current Moonwatch Professional example covered here is a 42 mm, manually wound watch with caliber 3861. Choose between them chiefly by wrist fit, winding preference, and whether you want the Professional Moonwatch identity.
What is the difference between the Speedmaster Reduced and the Moonwatch?
The Reduced is a Speedmaster Automatic variant, commonly associated with reference 3510.50.00. The Moonwatch is the Speedmaster Moonwatch Professional: Omega’s current manual identifies reference 310.32.42.50.04.001 by that name and specifies a manual-winding caliber 3861. They are related in design, but the Reduced is not simply a smaller reference of the same Professional watch.
![[Omega] OMEGA Watch [2021 Omega 310.30.42.50.01.002 Speedmaster Moon Watch Professional Hand Winding See Through Back Chronograph Black 5 ATM Waterproof [Parallel Import], Black, Bracelet Type](https://m.media-amazon.com/images/I/41w4a0vIS+S._SL160_.jpg)
Specialist coverage dates production of the Reduced from 1988 to 2010, so buyers generally encounter it as a pre-owned watch. The cited Moonwatch manual documents a current product reference; it does not establish live availability or pricing. Fratello Watches discusses the Reduced’s identity and production period, while Omega’s user manuals identify the Professional reference.
How do their movements and winding differ?
Speedmaster Reduced: automatic caliber 3220
The Reduced’s caliber 3220 is automatic. Hodinkee describes it as an ETA-based movement combined with a Dubois-Dépraz chronograph module. That construction differs from the Moonwatch’s integrated manual-winding setup. A specific Reduced power-reserve figure is not established here, so it is better not to assume one from the Moonwatch specification.
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Moonwatch Professional: manual caliber 3861
The current cited Moonwatch uses caliber 3861, which Omega specifies as manually wound, with a 50-hour power reserve. That means winding is part of routine ownership; the Reduced winds itself through wrist motion during wear, though it can still require winding after it has stopped. For exact reference-specific Moonwatch details, consult the Omega manual. The movement description for the Reduced comes from Hodinkee’s coverage.
Which watch is smaller, and what do the specifications say?
Omega lists the cited Moonwatch Professional at 42 mm in case diameter. The Reduced is smaller: secondary reporting commonly gives about 38.5 mm for reference 3510.50, but no Omega Reduced specification sheet was located to confirm that measurement. Check the exact reference and dimensions before buying, particularly because measurements can vary across Speedmaster references.
Rank #2
- Model 310.32.42.50.01.001
| Specification | Speedmaster Reduced, commonly ref. 3510.50.00 | Moonwatch Professional, cited Omega reference |
|---|---|---|
| Case diameter | About 38.5 mm, commonly reported for 3510.50 by secondary coverage; verify the exact reference. The Watchology | 42 mm for ref. 310.32.42.50.04.001, according to Omega’s manual. |
| Movement and winding | Automatic caliber 3220; ETA-based base with Dubois-Dépraz chronograph module, as described by Hodinkee. | Manual-winding caliber 3861. |
| Power reserve | Not established by official Reduced documentation cited here. | 50 hours for ref. 310.32.42.50.04.001, according to Omega’s manual. |
| Water resistance | Secondary coverage reports 30 m, but that figure is not confirmed here by Omega documentation; verify for the exact watch. The Watchology | 5 bar (50 m) for ref. 310.32.42.50.04.001, according to Omega’s manual. |
| Thickness and lug-to-lug | Not established by the cited sources. | Omega reports 13.09 mm thickness and 47.50 mm lug-to-lug for a different 42 mm steel-on-steel Moonwatch reference, 310.20.42.50.01.001—not the manual reference above. Omega product sheet |
These are reference-specific figures, not a guarantee that every watch sold as a Reduced or Moonwatch has identical specifications. Water resistance in particular should be treated as a specification to verify on the individual watch, not as an invitation to use an older pre-owned watch in water without checking its condition.
Is the Reduced a Moonwatch?
The Reduced is a Speedmaster, but it is not the Speedmaster Moonwatch Professional. Omega’s current documentation uses “Speedmaster MOONWATCH PROFESSIONAL” for the cited Professional reference. The available sources establish the Reduced as a smaller commercial automatic alternative, not as the Professional model itself. They do not establish that the Reduced was the watch worn on lunar missions, so the two identities should not be conflated.
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Which one should you choose?
Choose the Reduced if fit and automatic winding matter most
- You prefer a smaller watch; reference 3510.50 is commonly reported at about 38.5 mm, subject to reference verification.
- You want an automatic Speedmaster rather than a manually wound watch.
- You are comfortable buying a discontinued model and assessing a particular pre-owned example.
Choose the Moonwatch Professional if you want the Professional model
- You want the watch Omega identifies as the Moonwatch Professional.
- A 42 mm case and manual winding suit your preferences.
- You want the cited caliber 3861 specification, including its 50-hour reserve and 5 bar (50 m) water resistance for the specified reference.
What to check when buying a pre-owned Reduced
Because Reduced examples are pre-owned, the condition and records of the individual watch matter as much as the model’s general specifications. Before committing, confirm the reference and ask for documentation that supports the watch’s service history. If records are incomplete or you are unsure about condition, have a qualified watchmaker or knowledgeable seller assess it. No current market price or live inventory is established here, so compare current offers independently rather than treating an old price as a valuation.
Rank #4
For historical context only, Fratello Watches reports that in 2000 a Hesalite Moonwatch Professional cost €2,180 and a Reduced 3510.50 cost €1,220. Those are historical euro prices reported in a 2026 article, not present-day used-market values. Fratello Watches.
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- Model 310.30.42.50.01.002
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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