Seiko Cal. 5640 - 386

Released in 1970, the Cal. 5640 with design code 386 was part of Seiko's domestic market collection. The Rotating bezel and 35mm case give it a distinctive presence on the wrist. [seikata-wm-be9adb09e33d]

Also known as: Helmet, Crown

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

35mm

Case Thickness

14.0mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

180m

Dial Color

Silver

Jewels

20j

Frequency

36,000 bph

Power Reserve

66 hours

Year

1970

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