Seiko Cal. 6638 - 436

The Seiko 6638-436 represents an important milestone in Seiko's 1999 lineup. Powered by the 6638 caliber with 28j jewels beating at 36,000 bph, it delivers a 53 hours power reserve. [seikata-wm-20f05e37435a]

Also known as: Bullhead, Bellmatic

Specifications

Movement

Quartz

Case Material

Two-Tone

Case Width

34mm

Case Thickness

15.5mm

Lug Width

19mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

110m

Dial Color

Navy

Jewels

28j

Frequency

36,000 bph

Power Reserve

53 hours

Year

1999

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