Seiko Cal. 6638 - 956

The Seiko 6638-956 represents an important milestone in Seiko's 1980 lineup. Powered by the 6638 caliber with 22j jewels beating at 36,000 bph, it delivers a 52 hours power reserve. [seikata-wm-9a0e2e2dcb88]

Also known as: Tuna

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

40mm

Case Thickness

15.5mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

150m

Dial Color

White

Jewels

22j

Frequency

36,000 bph

Power Reserve

52 hours

Year

1980

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