Seiko Cal. 6690 - 640

The 6690-640 is a sought-after Hand-Winding piece from Seiko's golden era. Powered by the 6690 caliber with 21j jewels beating at 28,800 bph, it delivers a 72 hours power reserve. [seikata-wm-bb40ee89f3b5]

Also known as: Bellmatic

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

36mm

Case Thickness

12.3mm

Lug Width

19mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

130m

Dial Color

Burgundy

Jewels

21j

Frequency

28,800 bph

Power Reserve

72 hours

Year

1967

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