Seiko Cal. 6640 - 994

The Seiko 6640-994 represents an important milestone in Seiko's 1970 lineup. Powered by the 6640 caliber with 22j jewels beating at 21,600 bph, it delivers a 53 hours power reserve. [seikata-wm-01b106875bb5]

Also known as: Bullhead, Baby Tuna

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

40mm

Case Thickness

11.0mm

Lug Width

20mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

50m

Dial Color

Champagne

Jewels

22j

Frequency

21,600 bph

Power Reserve

53 hours

Year

1970

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