Orient Bambino Open Heart vs Oris Aquis Date Calibre 400
Orient's timepiece meets Oris's diver
Quick Verdict
The Orient Bambino Open Heart ($250–$500) offers Orient In-House Automatic, hand-winding and hacking precision in the tier below the Oris Aquis Date Calibre 400 ($2,500–$5,000). The Bambino Open Heart measures 40.5mm and is rated 30m (3 ATM). The Aquis Date Calibre 400 counters with Swiss Made craftsmanship and 300m (30 ATM) water resistance. Both are exceptional watches for their respective tiers.
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Specifications Compared
| Feature | Orient Bambino Open Heart | Oris Aquis Date Calibre 400 |
|---|---|---|
| Price | $250–$500 | $2,500–$5,000 |
| Case Size | 40.5mm | 41.5mm |
| Movement | Automatic Caliber F6T22 | Automatic Calibre 400 |
| Caliber Type | Orient In-House Automatic, hand-winding and hacking | Oris In-House Manufacture |
| Power Reserve | 40 Hours | 120 Hours (5 Days) |
| Water Resistance | 30m (3 ATM) | 300m (30 ATM) |
| Crystal | Domed Mineral Crystal | Sapphire Crystal with Anti-Reflective Coating |
| Case Material | Stainless Steel | Stainless Steel |
| Origin | Japanese Movement | Swiss Made |
Category-by-Category Analysis
Design & Aesthetics
Orient's design language vs Oris's approach
The Orient Bambino Open Heart features a Stainless Steel case at 40.5mm with Domed Mineral Crystal protection. The Oris Aquis Date Calibre 400 offers Stainless Steel construction at 41.5mm with Sapphire Crystal with Anti-Reflective Coating. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Automatic Caliber F6T22 vs Automatic Calibre 400
The Bambino Open Heart runs the Automatic Caliber F6T22 (Orient In-House Automatic, hand-winding and hacking, 40 Hours power reserve) at 21,600 vph (3 Hz) frequency. The Aquis Date Calibre 400 uses the Automatic Calibre 400 (Oris In-House Manufacture, 120 Hours (5 Days) reserve) at 28,800 vph (4 Hz). The Aquis Date Calibre 400 offers a longer power reserve.
Wearability & Fit
40.5mm vs 41.5mm — different wrist presence
At 40.5mm, the Bambino Open Heart wears more compactly on smaller wrists compared to the Aquis Date Calibre 400 at 41.5mm. Water resistance differs: 30m (3 ATM) vs 300m (30 ATM).
Value & Cost of Ownership
Orient sits in the lower tier
The Orient Bambino Open Heart sits at $250–$500 and the Oris Aquis Date Calibre 400 at $2,500–$5,000. On the specs that outlast any price: the Bambino Open Heart uses Domed Mineral Crystal with 40 Hours, against Sapphire Crystal with Anti-Reflective Coating and 120 Hours (5 Days) on the Aquis Date Calibre 400. Service intervals are typically 5-7 years for both.
Water Resistance
30m (3 ATM) vs 300m (30 ATM)
The Bambino Open Heart is rated to 30m (3 ATM) while the Aquis Date Calibre 400 handles 300m (30 ATM). The Aquis Date Calibre 400 offers superior water resistance.
Our Verdict
Orient
Bambino Open Heart
Choose the Orient Bambino Open Heart if you prioritize Orient In-House Automatic, hand-winding and hacking engineering, Japanese Movement craftsmanship, and 30m (3 ATM) water resistance. At $250–$500, it delivers Automatic Caliber F6T22 with 40 Hours power reserve.
Check Price on AmazonOris
Aquis Date Calibre 400
Choose the Oris Aquis Date Calibre 400 if you value Oris In-House Manufacture technology, Swiss Made heritage, and 41.5mm proportions. At $2,500–$5,000, the Automatic Calibre 400 with 120 Hours (5 Days) power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Orient Bambino Open Heart and Oris Aquis Date Calibre 400 represent two distinct approaches to fine watchmaking — the Orient bringing Japanese Movement tradition while Oris delivers Swiss Made 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.