Seiko Cal. 6631 - 481

This Hand-Winding model from 1987 features a 37mm Hardlex-Coated Steel case. With its 18mm lug width and 8.1mm profile, it sits comfortably on most wrists. [seikata-wm-35b22d2ec134]

Also known as: Sumo, World Timer

Specifications

Movement

Hand-Winding

Case Material

Hardlex-Coated Steel

Case Width

37mm

Case Thickness

8.1mm

Lug Width

18mm

Crystal

Mineral

Bezel

Coin-Edge

Water Resistance

50m

Dial Color

Navy

Jewels

21j

Frequency

36,000 bph

Power Reserve

46 hours

Year

1987

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