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Omega 304. Speedmaster Co-Axial Master chronometer Moonphase Chronograph 18K / SS (31553)


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Condition: Pre-owned
Scope of delivery: Original box, no original papers
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Verified dealer from:
US - Boston
Reviews: 197
Trusted Seller since 2009
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Basic Info

Listing number 6SG8I6
Reference number 304.
Brand Omega
Model Speedmaster Professional Moonwatch Moonphase
Code 31553
Movement Automatic
Case material Gold/Steel
Year 2018
Condition Very good (Worn with little to no signs of wear)
Scope of delivery Original box, no original papers
Location United States of America, Massachusetts, Boston


Movement Automatic
Movement/Caliber 9904
Power reserve 60 h
Number of jewels 54


Case material Gold/Steel
Case diameter 44.2 mm
Thickness 17.4 mm
Water resistance 10 ATM
Glass Sapphire Glass


Clasp Fold clasp
Clasp material Steel


Moon phase, Chronograph, Date, Tachymeter


Display Back, Center Seconds, Chronometer, Screw-Down Crown


Omega Speedmaster 304., 30423445206001, 18k yellow gold bezel and stainless steel case on a grey alligator with steel deployant clasp, chronometer, anti-magnetic, display back, Automatic Omega 9904 movement, Date, Moon Phases, Chronograph, Diameter: 44.25 mm, Thickness: 17.4mm, sapphire crystal with anti-reflective treatments on both sides, water resistant, Like New with Omega box and warranty dated 05/2018. Email us about this watch Trade for this watch


This is a stainless steel and 18k yellow gold Omega Speedmaster 304. It has an alligator leather stap with a stainless steel deployment clasp, and a scratch resistant "top hat" domed sapphire crystal with anti-reflective coatings on both sides. It has an 18k gold screw down protected winding crown, two round gold chronograph push buttons, and there is an exhibition screw down sapphire display case back, engraved with "MOONPHASE – LIQUIDMETAL – 100M-330 FT." The green ceramic bezel ring has a gold tachymeter scale to 500 UPH. The 44.25mm diameter solid three-body case, curved lugs, and 18k gold flat bezel, are polished/brushed. The dial is brushed steel with a sunray pattern. It has gold pointed baton hands with luminous Super-LumiNova inserts, and applied faceted gold baton hour markers with luminous inserts; "Speedmaster" is printed in red. There is a steel center sweep seconds hand with a luminous arrow indicator and a red needle tip, and around the perimeter is a minute/one-fifth second scale. At 6 o'clock is the realistic Moon phase indicator; it features a metallic crystal disc that's "micro-structured" to produce an extremely high-resolution image of the moon. There are twin black recessed gold-rimmed subsidiary dials, including a small running seconds indicator at 9 o'clock with a radial date scale indicated with a red crescent. A 12-hour chronograph totalizer is at the 3 o'clock position. It has a 60-hour power reserve at full winding, and it's water resistant to 100 meters/330 feet. It has a Certified Master Chronometer rating approved by METAS, it's resistant to magnetic fields reaching 15,000 gauss, and the 17.4mm thick case, dial, and movement are all signed.

This Omega Speedmaster Professional Moon watch Moon phase 304. has a mechanical automatic self-winding Omega caliber 9904 (base Omega 9300) movement. It has a column wheel chronograph and an Omega Co-Axial escapement. It's rhodium plated, and it's constructed with 54 jewels, 368 components, and a shock absorber device. It includes an Omega's Si14 silicon balance spring, twin barrels mounted in series, and the rotor & visible bridges are embellished with an arabesque wave design. The mechanism oscillates at a frequency of 28,800 vph (4 Hz).

The Omega Speedmaster Professional Moon watch Moon phase 304. was introduced in 2016.


European Watch Company

232 Newbury Street,
Boston, MA 02116
United States of America
Show phone/fax number
Tel.: [+1] 617-262-9798
Fax: [+1] 617-247-0480
We speak:
  • Chinese (simplified)
  • German
  • English
  • Spanish
  • Croatian
  • Chinese (traditional)
Trusted Seller since 2009
225 watches listed
This dealer owns a store in which you may view their watches.
Number of recommendations from other Chrono24 dealers: 8
Number of watches sold via Trusted Checkout: 331

4.9 out of 5 stars  |  Reviews: 197

Detailed explanation of ratings 

 4.9 Shipping
 4.8 Item description
 4.9 Communication
of buyers would recommend this dealer.

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