Seiko Cal. 6638 - 471

The Seiko 6638-471 represents an important milestone in Seiko's 1981 lineup. Powered by the 6638 caliber with 23j jewels beating at 28,800 bph, it delivers a 50 hours power reserve. [seikata-wm-c8731f856ab5]

Also known as: Helmet, Crown

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

36mm

Case Thickness

8.1mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Bidirectional

Water Resistance

130m

Dial Color

Black

Jewels

23j

Frequency

28,800 bph

Power Reserve

50 hours

Year

1981

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