Seiko Cal. 6638 - 691

Released in 1978, the Cal. 6638 with design code 691 was part of Seiko's domestic market collection. The Coin-Edge bezel and 39mm case give it a distinctive presence on the wrist. [seikata-wm-327cb86af220]

Also known as: Panda, Baby Tuna

Specifications

Movement

Solar

Case Material

Two-Tone

Case Width

39mm

Case Thickness

9.1mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

140m

Dial Color

Silver

Jewels

31j

Frequency

36,000 bph

Power Reserve

37 hours

Year

1978

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