Seiko

Prospex

SPB381
$1,500
MSRP

Specifications

Case Diameter
42mm
Lug to Lug
48.6mm
Thickness
12.9mm
Lug Width
20mm
Material
SS
Dial
Green
Movement
automatic
Caliber
6R54
Crystal
Sapphire
Strap
Bracelet

Pricing & Fit Summary

With a lug-to-lug measurement of 48.6mm, this reference is generally recommended for wrist sizes 14.6cm and larger. Note: fit is determined by lug-to-lug distance (48.6mm), not case diameter (42mm).

42mm
Diameter
48.6mm
Lug to Lug
12.9mm
Thickness
20mm
Lug Width
Caliber
6R54
Movement
Automatic
Crystal
Sapphire
Case Material
SS
Dial
Green
Strap
Bracelet
MSRP:
$1,500
Introduced:
2023

Perceived Size

How it wears, not just how it measures

~51mm

vs 49mm L2L

Compact (36mm)Substantial (60mm)

12.9mm case thickness adds +1.9mm wrist presence

Will this fit your wrist?

Slide to your wrist circumference to see the fit diagram.

Wrist circumference17 cm
12cm17cm (avg)22cm