Seiko Cal. 6638 - 561

The Seiko 6638-561 represents an important milestone in Seiko's 1965 lineup. Powered by the 6638 caliber with 35j jewels beating at 36,000 bph, it delivers a 49 hours power reserve. [seikata-wm-4cf6ca3af5d8]

Also known as: Sea Horse, Baby Tuna

Specifications

Movement

Solar

Case Material

Stainless Steel

Case Width

37mm

Case Thickness

10.8mm

Lug Width

22mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

200m

Dial Color

White

Jewels

35j

Frequency

36,000 bph

Power Reserve

49 hours

Year

1965

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