Side by side

Seiko Prospex SPEEDTIMER Mechanical ChronographvsZelos Helica Moonphase

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

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 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.

Zelos Helica Moonphase

Owners widely praise the Zelos Helica Moonphase for its gorgeous aventurine dial, unique industrial-dress aesthetic, and comfortable wearability, with one owner calling it spectacular and another their favorite Zelos. The moonphase complication is frequently highlighted as beautiful, though some find the double moon distracting or the dial cluttered. A manual-wind movement combined with a screw-down crown is noted as a drawback by some, requiring adjustment and potentially feeling fragile when fully wound, while one owner reports a 43-hour power reserve. On balance, owners rate the Zelos Helica Moonphase highly for its stunning aventurine dial and unique design at its price point.

At a glance

13 of 29 specs differ
Diameter
Prospex SPEEDTIMER Mechanical Chronograph42mm
Helica Moonphase39mm
Power Reserve
Prospex SPEEDTIMER Mechanical Chronograph45h
Helica Moonphase
Water Resistance
Prospex SPEEDTIMER Mechanical Chronograph100m
Helica Moonphase100m
MSRP
Prospex SPEEDTIMER Mechanical Chronograph$2,500
Helica Moonphase$1,049

Full specifications

Case

5 specs
Category
Chronograph
Moonphase
Diameter
42mm
39mm
Thickness
14.6mm
10mm
Lug-to-Lug
49.5mm
39mm
Material
Stainless Steel
316L Stainless Steel

Crystal & Dial

4 specs
Crystal Shape
Curved
AR Coating
Anti-reflective coating on inner surface
Dial Color
Meteorite
Lume
LumiBrite on hands and index(es)
None

Movement

3 specs
Caliber
8R48
Sellita SW288 Moonphase
Power Reserve
45h
0h
Jewels
34
0

Pricing

1 specs
MSRP
$2,500
$1,049
Keep exploring

More watches worth a look

Matched to the watches above on size, movement, style and price — microbrands first. Open any one to dig in.

Follow this matchup

Get a note when Seiko Prospex SPEEDTIMER Mechanical Chronograph vs Zelos Helica Moonphase gets more votes, a community discussion, or a price drop. No account needed.

Adjacent matchups

People also compared

Comparisons nearby in the catalog — alternatives to the watches above paired against the matchup.