Seiko Cal. 6643 - 157

The Seiko 6643-157 represents an important milestone in Seiko's 1978 lineup. Powered by the 6643 caliber with 30j jewels beating at 28,800 bph, it delivers a 63 hours power reserve. [seikata-wm-304daf95a0e9]

Also known as: Bullhead, Sea Horse

Specifications

Movement

Automatic

Case Material

Two-Tone

Case Width

37mm

Case Thickness

14.2mm

Lug Width

20mm

Crystal

Mineral

Bezel

Bidirectional

Water Resistance

40m

Dial Color

Burgundy

Jewels

30j

Frequency

28,800 bph

Power Reserve

63 hours

Year

1978

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