Which is bigger, the Slow Watches Slow Round 40mm or the Seiko Astron?

The Slow Watches Slow Round 40mm wears larger at 42.5mm versus 42mm for the Seiko Astron — a 0.5mm difference across the dial.

Which has better water resistance, the Slow Watches Slow Round 40mm or the Seiko Astron?

The Slow Watches Slow Round 40mm is rated to 100m versus 10m for the Seiko Astron.

What movement does the Slow Watches Slow Round 40mm run compared to the Seiko Astron?

Both watches run quartz movements — the Slow Watches Slow Round 40mm uses the Ronda 515.24 and the Seiko Astron uses the 5X83.

Side by side

Slow Watches Slow Round 40mmvsSeiko Astron

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

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Slow Watches Slow Round 40mm

slow-round-18

Seiko Astron

ssh159j1

MSRP $2,500

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At a glance

13 of 29 specs differ

Diameter

Slow Round 40mm42.5mm

Astron42mm

Power Reserve

Slow Round 40mm—

Astron40h

Water Resistance

Slow Round 40mm100m

Astron100m

MSRP

Slow Round 40mm—

Astron$2,500

Full specifications

Case

6 specs

Crystal & Dial

3 specs

AR Coating

Inner

Super-clear coating

Dial Color

—

Black

Lume

None

LumiBrite on hands and index(es)

Movement

3 specs

Caliber

Ronda 515.24

5X83

Power Reserve

—

40h

Jewels

Pricing

1 specs

MSRP

—

$2,500

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Slow Watches Slow Round 40mmvsSeiko Astron

At a glance

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