Seiko Presage SSA425 Open Heart vs Seiko Prospex 62MAS Modern Re-interpretation
Seiko's timepiece meets Seiko's diver
Quick Verdict
The Seiko Presage SSA425 Open Heart ($250–$500) offers Seiko In-House Automatic precision in the tier below the Seiko Prospex 62MAS Modern Re-interpretation ($1,000–$1,500). The Presage SSA425 Open Heart measures 40.5mm and is rated 50m (5 ATM). The Prospex 62MAS Modern Re-interpretation counters with Made in Japan craftsmanship and 200m (20 ATM) water resistance. Both are exceptional watches for their respective tiers.
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Specifications Compared
| Feature | Seiko Presage SSA425 Open Heart | Seiko Prospex 62MAS Modern Re-interpretation |
|---|---|---|
| Price | $250–$500 | $1,000–$1,500 |
| Case Size | 40.5mm | 40.5mm |
| Movement | Automatic Caliber 4R38 | Automatic 6R35 |
| Caliber Type | Seiko In-House Automatic | Seiko In-House Automatic |
| Power Reserve | 41 Hours | 70 Hours |
| Water Resistance | 50m (5 ATM) | 200m (20 ATM) |
| Crystal | Hardlex Crystal | Sapphire |
| Case Material | Stainless Steel | Stainless Steel with Super-Hard Coating |
| Origin | Made in Japan | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Seiko's design language vs Seiko's approach
The Seiko Presage SSA425 Open Heart features a Stainless Steel case at 40.5mm with Hardlex Crystal protection. The Seiko Prospex 62MAS Modern Re-interpretation offers Stainless Steel with Super-Hard Coating construction at 40.5mm with Sapphire. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Automatic Caliber 4R38 vs Automatic 6R35
The Presage SSA425 Open Heart runs the Automatic Caliber 4R38 (Seiko In-House Automatic, 41 Hours power reserve) at 21,600 vph (3 Hz) frequency. The Prospex 62MAS Modern Re-interpretation uses the Automatic 6R35 (Seiko In-House Automatic, 70 Hours reserve) at 21,600 vph (3 Hz). The Prospex 62MAS Modern Re-interpretation offers a longer power reserve.
Wearability & Fit
40.5mm vs 40.5mm — different wrist presence
At 40.5mm, the Presage SSA425 Open Heart is similarly sized compared to the Prospex 62MAS Modern Re-interpretation at 40.5mm. Water resistance differs: 50m (5 ATM) vs 200m (20 ATM).
Value & Cost of Ownership
Seiko sits in the lower tier
The Seiko Presage SSA425 Open Heart sits at $250–$500 and the Seiko Prospex 62MAS Modern Re-interpretation at $1,000–$1,500. On the specs that outlast any price: the Presage SSA425 Open Heart uses Hardlex Crystal with 41 Hours, against Sapphire and 70 Hours on the Prospex 62MAS Modern Re-interpretation. Service intervals are typically 5-7 years for both.
Water Resistance
50m (5 ATM) vs 200m (20 ATM)
The Presage SSA425 Open Heart is rated to 50m (5 ATM) while the Prospex 62MAS Modern Re-interpretation handles 200m (20 ATM). The Prospex 62MAS Modern Re-interpretation offers superior water resistance.
Our Verdict
Seiko
Presage SSA425 Open Heart
Choose the Seiko Presage SSA425 Open Heart if you prioritize Seiko In-House Automatic engineering, Made in Japan craftsmanship, and 50m (5 ATM) water resistance. At $250–$500, it delivers Automatic Caliber 4R38 with 41 Hours power reserve.
Check Price on AmazonSeiko
Prospex 62MAS Modern Re-interpretation
Choose the Seiko Prospex 62MAS Modern Re-interpretation if you value Seiko In-House Automatic technology, Made in Japan heritage, and 40.5mm proportions. At $1,000–$1,500, the Automatic 6R35 with 70 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Seiko Presage SSA425 Open Heart and Seiko Prospex 62MAS Modern Re-interpretation represent two distinct approaches to fine watchmaking — the Seiko bringing Made in Japan 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.