Seiko Cal. 5647 - 638

The Seiko 5647-638 represents an important milestone in Seiko's 1974 lineup. With its 22mm lug width and 8.2mm profile, it sits comfortably on most wrists. [seikata-wm-796a4caa2dbf]

Also known as: Helmet, Sportsmatic

Specifications

Movement

Hand-Winding

Case Material

Hardlex-Coated Steel

Case Width

46mm

Case Thickness

8.2mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

130m

Dial Color

Champagne

Jewels

23j

Frequency

36,000 bph

Power Reserve

42 hours

Year

1974

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