Seiko Cal. 6638 - 770

The 6638-770 is a sought-after Hand-Winding piece from Seiko's golden era. Powered by the 6638 caliber with 34j jewels beating at 36,000 bph, it delivers a 60 hours power reserve. [seikata-wm-da86435d6035]

Also known as: Bellmatic

Specifications

Movement

Hand-Winding

Case Material

Hardlex-Coated Steel

Case Width

35mm

Case Thickness

8.6mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

40m

Dial Color

Blue Sunburst

Jewels

34j

Frequency

36,000 bph

Power Reserve

60 hours

Year

1970

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