Seiko Cal. 6638 - 423

The Seiko 6638-423 represents an important milestone in Seiko's 1986 lineup. Powered by the 6638 caliber with 33j jewels beating at 28,800 bph, it delivers a 40 hours power reserve. [seikata-wm-d07e94e5ca54]

Also known as: Silverwave, Navigator

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

46mm

Case Thickness

10.6mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

200m

Dial Color

Black

Jewels

33j

Frequency

28,800 bph

Power Reserve

40 hours

Year

1986

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