Seiko Cal. 0731 - 639

This Quartz model from 1979 features a 40mm Hardlex-Coated Steel case. Powered by the 0731 caliber with 17j jewels beating at 28,800 bph, it delivers a 58 hours power reserve. [seikata-wm-db223b51c019]

Also known as: Tuna, Bullhead

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

40mm

Case Thickness

9.9mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

70m

Dial Color

Black

Jewels

17j

Frequency

28,800 bph

Power Reserve

58 hours

Year

1979

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