Seiko Cal. 6637 - 740

This Hand-Winding model from 1993 features a 41mm Two-Tone case. With its 20mm lug width and 11.9mm profile, it sits comfortably on most wrists. [seikata-wm-d1dfcc15cdd7]

Also known as: Tuna, Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

41mm

Case Thickness

11.9mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

180m

Dial Color

Green

Jewels

34j

Frequency

36,000 bph

Power Reserve

71 hours

Year

1993

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