Seiko Cal. 6631 - 101

This Hand-Winding model from 1978 features a 45mm Titanium case. Powered by the 6631 caliber with 21j jewels beating at 36,000 bph, it delivers a 62 hours power reserve. [seikata-wm-b4897d0b7c7c]

Also known as: Sportsmatic, Baby Tuna

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

45mm

Case Thickness

11.0mm

Lug Width

21mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

110m

Dial Color

Champagne

Jewels

21j

Frequency

36,000 bph

Power Reserve

62 hours

Year

1978

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