Seiko Cal. 3864 - 645

Released in 1988, the Cal. 3864 with design code 645 was part of Seiko's domestic market collection. With its 22mm lug width and 9.4mm profile, it sits comfortably on most wrists. [seikata-wm-171ced67fd55]

Also known as: Sumo, Bellmatic

Specifications

Movement

Solar

Case Material

Hardlex-Coated Steel

Case Width

40mm

Case Thickness

9.4mm

Lug Width

22mm

Crystal

Mineral

Bezel

Bidirectional

Water Resistance

140m

Dial Color

Navy

Jewels

32j

Frequency

28,800 bph

Power Reserve

71 hours

Year

1988

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