Side by side

Formex Reef 39.5 mmvsGrand Seiko SBGN027

The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.

Reef 39.5 mm
FormexReef 39.5 mm
MSRP $2,230
SBGN027
Grand SeikoSBGN027
MSRP $3,700

At a glance

13 of 29 specs differ
Diameter
Reef 39.5 mm39.5mm
SBGN02739mm
Power Reserve
Reef 39.5 mm56h
SBGN02740h
Water Resistance
Reef 39.5 mm300m
SBGN027200m
MSRP
Reef 39.5 mm$2,230
SBGN027$3,700

Full specifications

Case

6 specs
Category
Diver
GMT
Diameter
39.5mm
39mm
Thickness
11mm
12.3mm
Lug-to-Lug
45.5mm
45.9mm
Lug Width
22mm
19mm
Water Resistance
300m
200m

Crystal & Dial

3 specs
AR Coating
Inner
Yes
Dial Color
Bahama Blue
Black
Lume
Super-LumiNova
None

Movement

3 specs
Caliber
Sellita SW300-1
9F86
Type
Automatic
Quartz
Power Reserve
56h
40h

Pricing

1 specs
MSRP
$2,230
$3,700

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What people say

Owners + reviewers, side by side

Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.

Formex Reef 39.5 mm

The Formex Reef 39.5 mm is widely praised for its refined finishing, comfortable and well-proportioned case design, and impressive specifications for its price point, including COSC-certified Sellita SW300-1 movement and 300m water resistance. Owners and reviewers highlight the tool-less micro-adjust clasp and quick-release spring bars as practical features. Some reviewers note that the 22mm lug width feels slightly disproportionate to the smaller case, and the bracelet could benefit from more taper, though this is a point of contention for some owners who value the overall package. A prototype crown protrusion issue is noted as being addressed for production. On balance, owners and reviewers rate the Formex Reef 39.5 mm highly for its excellent value and well-executed design.

Grand Seiko SBGN027

Owners widely praise the Grand Seiko SBGN027 for its exceptional Zaratsu polishing, compact 39mm size, and versatile monochrome aesthetic, noting its thin profile and suitability as a grab-and-go watch. The 9F quartz movement delivers highly accurate timekeeping, with one owner reporting +/- 10 seconds per year. However, some find the lume limited, the bracelet lacks micro-adjustments, and the GMT hand can be easily mistaken for the minute hand. One owner reported a black index on the bezel disappearing after a couple of months. On balance, owners rate the Grand Seiko SBGN027 highly for its premium finishing and accurate HAQ GMT movement in a wearable size.

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