Seiko Cal. 3840 - 139

Released in 1974, the Cal. 3840 with design code 139 was part of Seiko's domestic market collection. The Bidirectional bezel and 46mm case give it a distinctive presence on the wrist. [seikata-wm-0803d03ad6ce]

Also known as: Sumo, Helmet

Specifications

Movement

Solar

Case Material

PVD Black

Case Width

46mm

Case Thickness

11.3mm

Lug Width

21mm

Crystal

Acrylic

Bezel

Bidirectional

Water Resistance

150m

Dial Color

White

Jewels

22j

Frequency

36,000 bph

Power Reserve

62 hours

Year

1974

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