Side by side

Seiko Prospex SPEEDTIMER MechanicalvsGruppo Gamma Field III GMT

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

Prospex SPEEDTIMER Mechanical
SeikoProspex SPEEDTIMER Mechanical
MSRP $995
Field III GMT
Gruppo GammaField III GMT
MSRP $459

At a glance

13 of 29 specs differ
Diameter
Prospex SPEEDTIMER Mechanical39.5mm
Field III GMT40mm
Power Reserve
Prospex SPEEDTIMER Mechanical72h
Field III GMT41h
Water Resistance
Prospex SPEEDTIMER Mechanical200m
Field III GMT200m
MSRP
Prospex SPEEDTIMER Mechanical$995
Field III GMT$459

Full specifications

Case

5 specs
Category
Chronograph
GMT
Diameter
39.5mm
40mm
Thickness
12mm
14mm
Lug-to-Lug
44.5mm
48.5mm
Lug Width
20mm
22mm

Crystal & Dial

3 specs
Crystal Shape
Curved
Flat
AR Coating
Anti-reflective coating on inner surface
Yes
Lume
LumiBrite on hands and index(es)
Super-LumiNova

Movement

4 specs
Caliber
6R55
Seiko Instruments NH38A
Power Reserve
72h
41h
Jewels
24
25
Complications
None
GMT

Pricing

1 specs
MSRP
$995
$459

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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.

Seiko Prospex SPEEDTIMER Mechanical

The Seiko Prospex SPEEDTIMER Mechanical is praised for its visually appealing design and comfortable wearability, with owners frequently using its chronograph function for daily tasks. Reviewers note its clean dial layout and LumiBrite treated hands and markers, and one source highlights the 72-hour power reserve of the 6R55 movement. However, some owners criticize its chronograph functionality and the 24-hour subdial. On balance, owners and reviewers rate the Seiko Prospex SPEEDTIMER Mechanical highly for its daily usability and refined aesthetics.

Gruppo Gamma Field III GMT

Owners praise the Gruppo Gamma Field III GMT for its look and value, with specific mentions of its sandwich dial and comfortable OEM straps. One owner notes incredible quality for the price across their Gruppo Gamma watches. The watch features a 40mm brushed stainless steel case, box sapphire crystal, and a Seiko NH34A movement with a 41-hour power reserve and stated accuracy of -20~+40 s/day. Some find the lack of a date window a drawback for a GMT, and question its differentiation from other NH34-powered watches. On balance, owners and reviewers find the Gruppo Gamma Field III GMT to be a good value with quality construction for its price point.

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