Seiko Cal. 5640 - 188

The 5640-188 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 5640 caliber with 35j jewels beating at 36,000 bph, it delivers a 67 hours power reserve. [seikata-wm-ea4adbeac039]

Also known as: Bullhead

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

41mm

Case Thickness

12.4mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

110m

Dial Color

Navy

Jewels

35j

Frequency

36,000 bph

Power Reserve

67 hours

Year

1973

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