Seiko Cal. 6640 - 178

The Seiko 6640-178 represents an important milestone in Seiko's 1998 lineup. Powered by the 6640 caliber with 17j jewels beating at 36,000 bph, it delivers a 69 hours power reserve. [seikata-wm-6053211c9cf3]

Also known as: Bullhead, Crown

Specifications

Movement

Solar

Case Material

Stainless Steel

Case Width

41mm

Case Thickness

12.1mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

100m

Dial Color

White

Jewels

17j

Frequency

36,000 bph

Power Reserve

69 hours

Year

1998

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