Seiko Cal. 6643 - 581

The 6643-581 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 6643 caliber with 20j jewels beating at 21,600 bph, it delivers a 67 hours power reserve. [seikata-wm-e3d54bde20dd]

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

46mm

Case Thickness

8.0mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

170m

Dial Color

Blue Sunburst

Jewels

20j

Frequency

21,600 bph

Power Reserve

67 hours

Year

1975

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