Orient Mako 40 Green vs Seiko 5 Sports GMT SSK001
Orient's diver meets Seiko's GMT watch
Quick Verdict
The Orient Mako 40 Green ($250–$500) and Seiko 5 Sports GMT SSK001 ($250–$500) are closely matched timepieces at similar price points. The Mako 40 Green emphasizes Orient In-House Automatic (Hacking, Hand-Winding) engineering while the 5 Sports GMT SSK001 focuses on Made in Japan craftsmanship.
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Specifications Compared
| Feature | Orient Mako 40 Green | Seiko 5 Sports GMT SSK001 |
|---|---|---|
| Price | $250–$500 | $250–$500 |
| Case Size | 40mm | 42.5mm |
| Movement | Automatic Caliber F6722 | Automatic Caliber 4R34 (True GMT) |
| Caliber Type | Orient In-House Automatic (Hacking, Hand-Winding) | Seiko In-House Automatic GMT |
| Power Reserve | 40 Hours | 41 Hours |
| Water Resistance | 200m (20 ATM) | 100m (10 ATM) |
| Crystal | Sapphire Crystal | Hardlex Crystal |
| Case Material | Stainless Steel | Stainless Steel |
| Origin | Made in Japan | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Orient's design language vs Seiko's approach
The Orient Mako 40 Green features a Stainless Steel case at 40mm with Sapphire Crystal 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
Automatic Caliber F6722 vs Automatic Caliber 4R34 (True GMT)
The Mako 40 Green runs the Automatic Caliber F6722 (Orient In-House Automatic (Hacking, Hand-Winding), 40 Hours power reserve) at 21,600 vph (3 Hz) 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
40mm vs 42.5mm — different wrist presence
At 40mm, the Mako 40 Green wears more compactly on smaller wrists compared to the 5 Sports GMT SSK001 at 42.5mm. Water resistance differs: 200m (20 ATM) vs 100m (10 ATM).
Value & Cost of Ownership
Same tier — different value propositions
The Orient Mako 40 Green sits at $250–$500 and the Seiko 5 Sports GMT SSK001 at $250–$500. On the specs that outlast any price: the Mako 40 Green uses Sapphire Crystal with 40 Hours, against Hardlex Crystal and 41 Hours on the 5 Sports GMT SSK001. Service intervals are typically 5-7 years for both.
Water Resistance
200m (20 ATM) vs 100m (10 ATM)
The Mako 40 Green is rated to 200m (20 ATM) while the 5 Sports GMT SSK001 handles 100m (10 ATM). The Mako 40 Green is better suited for water activities.
Our Verdict
Orient
Mako 40 Green
Choose the Orient Mako 40 Green if you prioritize Orient In-House Automatic (Hacking, Hand-Winding) engineering, Made in Japan craftsmanship, and 200m (20 ATM) water resistance. At $250–$500, it delivers Automatic Caliber F6722 with 40 Hours 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 Orient Mako 40 Green and Seiko 5 Sports GMT SSK001 represent two distinct approaches to fine watchmaking — the Orient 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.