Seiko Cal. 6640 - 401

This Spring Drive model from 1996 features a 39mm Hardlex-Coated Steel case. Powered by the 6640 caliber with 22j jewels beating at 36,000 bph, it delivers a 40 hours power reserve. [seikata-wm-4df59a4af4f0]

Also known as: Helmet, Navigator

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

39mm

Case Thickness

14.5mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

120m

Dial Color

Champagne

Jewels

22j

Frequency

36,000 bph

Power Reserve

40 hours

Year

1996

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