Seiko Cal. 6661 - 728

The Seiko 6661-728 represents an important milestone in Seiko's 1978 lineup. Powered by the 6661 caliber with 24j jewels beating at 36,000 bph, it delivers a 71 hours power reserve. [seikata-wm-6555a3109acd]

Also known as: Helmet, Navigator

Specifications

Movement

Spring Drive

Case Material

Gold-Plated

Case Width

38mm

Case Thickness

10.9mm

Lug Width

22mm

Crystal

Mineral

Bezel

Rotating

Water Resistance

130m

Dial Color

Silver

Jewels

24j

Frequency

36,000 bph

Power Reserve

71 hours

Year

1978

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