The Titanium Field GuidePicks of the month

RDUNAE R1 Zaku Tuna-II

The RDUNAE R1 Zaku Tuna-II is a 52 mm titanium dive watch with a Seiko NH35 automatic movement. At 52 mm across, it is larger than 98% of the 359 titanium dive watches in the guide.

All RDUNAE watchesDiver watchesUnder $500Microbrand
Price
$209.9
Material
Titanium
Grade / type
Titanium (grade undisclosed)
Water resistance
500 m
Type
Diver
Case diameter
52.0 mm
Origin
China
Movement
Automatic
Caliber
Seiko NH35
Complications
Date
Colour
Grey
Surface treatment
IP-coated titanium; aluminium shroud
Finish technology
PVD / IP
Caseback
Titanium
Nickel-free
Unconfirmed (bracelet, strap, or clasp hardware not confirmed)
Display back
No
Dial
Green, red, and blue colourways
Dial colours
Blue Green Red
Availability
Offered
Status
Current
Not published
Reference, Thickness, Lug-to-lug, Weight, Power reserve, Hardness, Construction, Bracelet / strap, Matching bracelet, Crystal, Lume
Medium confidence Verified Sep 2026 Source: RDUNAE R1 Zaku Tuna-II Spec checksGrade Jul 2026Price Sep 2026
Facts are free to cite with a link.
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Frequently asked questions

What grade of titanium is the RDUNAE R1 Zaku Tuna-II?

Titanium, with no grade stated. The caseback is titanium too. The record is at medium confidence, so check the maker's page before relying on it.

What size is the RDUNAE R1 Zaku Tuna-II?

The case is 52 mm across. It is water resistant to 500 m.

How much does the RDUNAE R1 Zaku Tuna-II cost, and is it available?

It is in production, at a list price of $209.90.

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