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Breguet Classique 7137 Power Reserve Moonphase (18k yellow gold) vs Seiko Presage SSA425 Open Heart
Breguet's dress watch meets Seiko's timepiece
Quick Verdict
The Seiko Presage SSA425 Open Heart ($250–$500) delivers Seiko In-House Automatic technology in the tier below the Breguet Classique 7137 Power Reserve Moonphase (18k yellow gold) ($25,000+). The Presage SSA425 Open Heart measures 40.5mm and is rated 50m (5 ATM). The Classique 7137 Power Reserve Moonphase (18k yellow gold) justifies its premium with Swiss Made heritage and Automatic, Breguet Calibre 502.3 QSE1 (ultra-thin, off-centre rotor). Both represent excellent choices in the luxury watch category.
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Specifications Compared
| Feature | Breguet Classique 7137 Power Reserve Moonphase (18k yellow gold) | Seiko Presage SSA425 Open Heart |
|---|---|---|
| Price | $25,000+ | $250–$500 |
| Case Size | 39mm | 40.5mm |
| Movement | Automatic, Breguet Calibre 502.3 QSE1 (ultra-thin, off-centre rotor) | Automatic Caliber 4R38 |
| Caliber Type | Breguet 502.3 QSE1, automatic, silicon escapement | Seiko In-House Automatic |
| Power Reserve | About 45 hours, with indicator | 41 Hours |
| Water Resistance | 30m (3 ATM) | 50m (5 ATM) |
| Crystal | Sapphire Crystal, sapphire caseback | Hardlex Crystal |
| Case Material | 18k yellow gold, fluted caseband | Stainless Steel |
| Origin | Swiss Made | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Breguet's design language vs Seiko's approach
The Breguet Classique 7137 Power Reserve Moonphase (18k yellow gold) features a 18k yellow gold, fluted caseband case at 39mm with Sapphire Crystal, sapphire caseback protection. The Seiko Presage SSA425 Open Heart offers Stainless Steel construction at 40.5mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Automatic, Breguet Calibre 502.3 QSE1 (ultra-thin, off-centre rotor) vs Automatic Caliber 4R38
The Classique 7137 Power Reserve Moonphase (18k yellow gold) runs the Automatic, Breguet Calibre 502.3 QSE1 (ultra-thin, off-centre rotor) (Breguet 502.3 QSE1, automatic, silicon escapement, About 45 hours, with indicator power reserve) at standard frequency. The Presage SSA425 Open Heart uses the Automatic Caliber 4R38 (Seiko In-House Automatic, 41 Hours reserve) at 21,600 vph (3 Hz). The Classique 7137 Power Reserve Moonphase (18k yellow gold) edges ahead on power reserve.
Wearability & Fit
39mm vs 40.5mm — different wrist presence
At 39mm, the Classique 7137 Power Reserve Moonphase (18k yellow gold) wears more compactly on smaller wrists compared to the Presage SSA425 Open Heart at 40.5mm. Water resistance differs: 30m (3 ATM) vs 50m (5 ATM).
Value & Cost of Ownership
Seiko sits in the lower tier
The Breguet Classique 7137 Power Reserve Moonphase (18k yellow gold) sits at $25,000+ and the Seiko Presage SSA425 Open Heart at $250–$500. On the specs that outlast any price: the Classique 7137 Power Reserve Moonphase (18k yellow gold) uses Sapphire Crystal, sapphire caseback with About 45 hours, with indicator, against Hardlex Crystal and 41 Hours on the Presage SSA425 Open Heart. Service intervals are typically 5-7 years for both.
Water Resistance
30m (3 ATM) vs 50m (5 ATM)
The Classique 7137 Power Reserve Moonphase (18k yellow gold) is rated to 30m (3 ATM) while the Presage SSA425 Open Heart handles 50m (5 ATM). The Presage SSA425 Open Heart offers superior water resistance.
Our Verdict
Breguet
Classique 7137 Power Reserve Moonphase (18k yellow gold)
Choose the Breguet Classique 7137 Power Reserve Moonphase (18k yellow gold) if you prioritize Breguet 502.3 QSE1, automatic, silicon escapement engineering, Swiss Made craftsmanship, and 30m (3 ATM) water resistance. At $25,000+, it delivers Automatic, Breguet Calibre 502.3 QSE1 (ultra-thin, off-centre rotor) with About 45 hours, with indicator power reserve.
Check Price on AmazonSeiko
Presage SSA425 Open Heart
Choose the Seiko Presage SSA425 Open Heart if you value Seiko In-House Automatic technology, Made in Japan heritage, and 40.5mm proportions. At $250–$500, the Automatic Caliber 4R38 with 41 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Breguet Classique 7137 Power Reserve Moonphase (18k yellow gold) and Seiko Presage SSA425 Open Heart represent two distinct approaches to fine watchmaking — the Breguet bringing Swiss Made tradition while Seiko delivers Made in Japan engineering.
Frequently Asked Questions
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How This Page Was Made
Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.