Head-to-Head Comparison

Updated

Casio Pro Trek PRW3500T-7 vs Orient Bambino Open Heart

Casio's diver meets Orient's timepiece

Quick Verdict

The Casio Pro Trek PRW3500T-7 ($250–$500) and Orient Bambino Open Heart ($250–$500) are closely matched timepieces at similar price points. The Pro Trek PRW3500T-7 emphasizes Tough Solar Quartz, Multi-Band 6 engineering while the Bambino Open Heart focuses on Japanese Movement craftsmanship.

Transparency — We earn a small commission on purchases made through our Amazon links. This doesn't affect our editorial independence.

Casio Pro Trek PRW3500T-7

Casio

Pro Trek PRW3500T-7

$250–$500

Orient Bambino Open Heart

Orient

Bambino Open Heart

$250–$500

Specifications Compared

FeatureCasio Pro Trek PRW3500T-7Orient Bambino Open Heart
Price$250–$500$250–$500
Case Size56.9 × 53.4 × 14.8mm40.5mm
MovementTough Solar (Solar Quartz), Radio-ControlledAutomatic Caliber F6T22
Caliber TypeTough Solar Quartz, Multi-Band 6Orient In-House Automatic, hand-winding and hacking
Power ReserveTough Solar (Rechargeable)40 Hours
Water Resistance200m (20 ATM)30m (3 ATM)
CrystalMineral GlassDomed Mineral Crystal
Case MaterialResin / Stainless Steel, Titanium BraceletStainless Steel
OriginCasio (Japan)Japanese Movement

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Casio's design language vs Orient's approach

The Casio Pro Trek PRW3500T-7 features a Resin / Stainless Steel, Titanium Bracelet case at 56.9 × 53.4 × 14.8mm with Mineral Glass protection. The Orient Bambino Open Heart offers Stainless Steel construction at 40.5mm with Domed Mineral Crystal. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Orient

Tough Solar (Solar Quartz), Radio-Controlled vs Automatic Caliber F6T22

The Pro Trek PRW3500T-7 runs the Tough Solar (Solar Quartz), Radio-Controlled (Tough Solar Quartz, Multi-Band 6, Tough Solar (Rechargeable) power reserve) at standard frequency. The Bambino Open Heart uses the Automatic Caliber F6T22 (Orient In-House Automatic, hand-winding and hacking, 40 Hours reserve) at 21,600 vph (3 Hz). The Bambino Open Heart offers a longer power reserve.

📏

Wearability & Fit

Edge: Orient

56.9 × 53.4 × 14.8mm vs 40.5mm — different wrist presence

At 56.9 × 53.4 × 14.8mm, the Pro Trek PRW3500T-7 has a bolder wrist presence compared to the Bambino Open Heart at 40.5mm. Water resistance differs: 200m (20 ATM) vs 30m (3 ATM).

💰

Value & Cost of Ownership

Edge: Draw

Same tier — different value propositions

The Casio Pro Trek PRW3500T-7 sits at $250–$500 and the Orient Bambino Open Heart at $250–$500. On the specs that outlast any price: the Pro Trek PRW3500T-7 uses Mineral Glass with Tough Solar (Rechargeable), against Domed Mineral Crystal and 40 Hours on the Bambino Open Heart. Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Casio

200m (20 ATM) vs 30m (3 ATM)

The Pro Trek PRW3500T-7 is rated to 200m (20 ATM) while the Bambino Open Heart handles 30m (3 ATM). The Pro Trek PRW3500T-7 is better suited for water activities.

Our Verdict

Casio

Pro Trek PRW3500T-7

Choose the Casio Pro Trek PRW3500T-7 if you prioritize Tough Solar Quartz, Multi-Band 6 engineering, Casio (Japan) craftsmanship, and 200m (20 ATM) water resistance. At $250–$500, it delivers Tough Solar (Solar Quartz), Radio-Controlled with Tough Solar (Rechargeable) power reserve.

Check Price on Amazon

Orient

Bambino Open Heart

Choose the Orient Bambino Open Heart if you value Orient In-House Automatic, hand-winding and hacking technology, Japanese Movement heritage, and 40.5mm proportions. At $250–$500, the Automatic Caliber F6T22 with 40 Hours power reserve makes it a compelling choice.

View the dossier

The Bottom Line

The Casio Pro Trek PRW3500T-7 and Orient Bambino Open Heart represent two distinct approaches to fine watchmaking — the Casio bringing Casio (Japan) tradition while Orient delivers Japanese Movement engineering.

Frequently Asked Questions

The Orient Bambino Open Heart is the better buy if you want a mechanical movement; the Casio Pro Trek PRW3500T-7 is the better buy if you want solar power and quartz accuracy with no servicing. For water, the Casio Pro Trek PRW3500T-7 is rated 200 m against 30 m, which is the difference between swimming and diving on one side and splashes on the other. Neither is better at everything; the spec table above shows movement, case size, water resistance and crystal side by side so you can weigh what matters to you. We do not test units, so this is the makers' data, not a bench result.
Both are priced similarly, making this a question of preference rather than value. The Pro Trek PRW3500T-7 emphasizes Tough Solar Quartz, Multi-Band 6 technology while the Bambino Open Heart prioritizes Orient In-House Automatic, hand-winding and hacking precision.
Both are suitable for daily wear. The Pro Trek PRW3500T-7 at 56.9 × 53.4 × 14.8mm with 200m (20 ATM) water resistance handles everyday situations. The Bambino Open Heart at 40.5mm with 30m (3 ATM) is similarly capable. The Pro Trek PRW3500T-7 uses Mineral Glass while the Bambino Open Heart uses Domed Mineral Crystal.

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.