Side by side

Formex Reef 42 mmvsSeiko Prospex SPEEDTIMER Mechanical Chronograph

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

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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 42 mm

The Formex Reef 42 mm is widely praised for its comfortable bracelet featuring a micro-adjust clasp, COSC-certified Sellita movement, and excellent build quality. Owners appreciate the gradient dial's visual appeal and the overall wearability. Some owners note the seconds hand does not perfectly align with markers, and one owner found the lugs' taper hinders third-party strap fit. The bracelet's length and sporty design are noted as limiting versatility by some. On balance, owners and reviewers rate the Formex Reef 42 mm highly for its impressive wearability and value at the price point.

Seiko Prospex SPEEDTIMER Mechanical Chronograph

The Seiko Prospex SPEEDTIMER Mechanical Chronograph is praised for its handsome, heritage-inspired design with a clean, balanced dial and an external tachymeter bezel. Reviewers highlight the upgraded case and bracelet, noting improved comfort and good value for a well-designed chronograph with an in-house movement. The caliber 8R48 movement features a vertical clutch and column wheel with MEMS technology for durability and precision. Points to consider include the 4:30 date window and a 14.6mm thickness, while the 45-hour power reserve is noted as an area for potential improvement. On balance, reviewers find the Seiko Prospex SPEEDTIMER Mechanical Chronograph to be a solid offering with good value, particularly for its design and in-house movement.

At a glance

13 of 29 specs differ
Diameter
Reef 42 mm42mm
Prospex SPEEDTIMER Mechanical Chronograph42mm
Power Reserve
Reef 42 mm56h
Prospex SPEEDTIMER Mechanical Chronograph45h
Water Resistance
Reef 42 mm300m
Prospex SPEEDTIMER Mechanical Chronograph100m
MSRP
Reef 42 mm$2,414
Prospex SPEEDTIMER Mechanical Chronograph$2,500

Full specifications

Case

5 specs
Category
Diver
Chronograph
Thickness
11.4mm
14.6mm
Lug-to-Lug
47mm
49.5mm
Lug Width
22mm
20mm
Water Resistance
300m
100m

Crystal & Dial

4 specs
Crystal Shape
Curved
AR Coating
Anti-reflective coating on inner surface
Dial Color
Black
Lume
Super-LumiNova
LumiBrite on hands and index(es)

Movement

3 specs
Caliber
Sellita SW300-1
Seiko 8R48
Power Reserve
56h
45h
Jewels
0
34

Pricing

1 specs
MSRP
$2,414
$2,500
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