Seiko Cal. 6643 - 957

The Seiko 6643-957 represents an important milestone in Seiko's 1971 lineup. Powered by the 6643 caliber with 27j jewels beating at 28,800 bph, it delivers a 43 hours power reserve. [seikata-wm-4438015dfefc]

Also known as: Helmet, Silverwave

Specifications

Movement

Automatic

Case Material

Two-Tone

Case Width

35mm

Case Thickness

13.3mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

170m

Dial Color

Green

Jewels

27j

Frequency

28,800 bph

Power Reserve

43 hours

Year

1971

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