Casio Pro Trek PRG601-1 vs Seiko 5 Sports GMT SSK001
Casio's timepiece meets Seiko's GMT watch
Quick Verdict
The Casio Pro Trek PRG601-1 ($250–$500) and Seiko 5 Sports GMT SSK001 ($250–$500) are closely matched timepieces at similar price points. The Pro Trek PRG601-1 emphasizes Tough Solar Quartz (No Battery Change) engineering while the 5 Sports GMT SSK001 focuses on Made in Japan craftsmanship.
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Specifications Compared
| Feature | Casio Pro Trek PRG601-1 | Seiko 5 Sports GMT SSK001 |
|---|---|---|
| Price | $250–$500 | $250–$500 |
| Case Size | 51.6mm | 42.5mm |
| Movement | Tough Solar (Solar Quartz) | Automatic Caliber 4R34 (True GMT) |
| Caliber Type | Tough Solar Quartz (No Battery Change) | Seiko In-House Automatic GMT |
| Power Reserve | 7 Months (Solar, Full Charge); 25 Months Power Save | 41 Hours |
| Water Resistance | 100m (10 ATM) | 100m (10 ATM) |
| Crystal | Mineral Glass | Hardlex Crystal |
| Case Material | Bio-Based Resin / Stainless Steel | Stainless Steel |
| Origin | Casio (Japan) | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Casio's design language vs Seiko's approach
The Casio Pro Trek PRG601-1 features a Bio-Based Resin / Stainless Steel case at 51.6mm with Mineral Glass protection. The Seiko 5 Sports GMT SSK001 offers Stainless Steel construction at 42.5mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Tough Solar (Solar Quartz) vs Automatic Caliber 4R34 (True GMT)
The Pro Trek PRG601-1 runs the Tough Solar (Solar Quartz) (Tough Solar Quartz (No Battery Change), 7 Months (Solar, Full Charge); 25 Months Power Save power reserve) at standard frequency. The 5 Sports GMT SSK001 uses the Automatic Caliber 4R34 (True GMT) (Seiko In-House Automatic GMT, 41 Hours reserve) at 21,600 vph (3 Hz). The 5 Sports GMT SSK001 offers a longer power reserve.
Wearability & Fit
51.6mm vs 42.5mm — different wrist presence
At 51.6mm, the Pro Trek PRG601-1 has a bolder wrist presence compared to the 5 Sports GMT SSK001 at 42.5mm. Water resistance differs: 100m (10 ATM) vs 100m (10 ATM).
Value & Cost of Ownership
Same tier — different value propositions
The Casio Pro Trek PRG601-1 sits at $250–$500 and the Seiko 5 Sports GMT SSK001 at $250–$500. On the specs that outlast any price: the Pro Trek PRG601-1 uses Mineral Glass with 7 Months (Solar, Full Charge); 25 Months Power Save, against Hardlex Crystal and 41 Hours on the 5 Sports GMT SSK001. Service intervals are typically 5-7 years for both.
Water Resistance
100m (10 ATM) vs 100m (10 ATM)
The Pro Trek PRG601-1 is rated to 100m (10 ATM) while the 5 Sports GMT SSK001 handles 100m (10 ATM). Both offer identical water resistance ratings.
Our Verdict
Casio
Pro Trek PRG601-1
Choose the Casio Pro Trek PRG601-1 if you prioritize Tough Solar Quartz (No Battery Change) engineering, Casio (Japan) craftsmanship, and 100m (10 ATM) water resistance. At $250–$500, it delivers Tough Solar (Solar Quartz) with 7 Months (Solar, Full Charge); 25 Months Power Save power reserve.
Check Price on AmazonSeiko
5 Sports GMT SSK001
Choose the Seiko 5 Sports GMT SSK001 if you value Seiko In-House Automatic GMT technology, Made in Japan heritage, and 42.5mm proportions. At $250–$500, the Automatic Caliber 4R34 (True GMT) with 41 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Casio Pro Trek PRG601-1 and Seiko 5 Sports GMT SSK001 represent two distinct approaches to fine watchmaking — the Casio bringing Casio (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.