Seiko Cal. 6638 - 536

The Seiko 6638-536 represents an important milestone in Seiko's 1998 lineup. The Coin-Edge bezel and 45mm case give it a distinctive presence on the wrist. [seikata-wm-76fd73a47bfa]

Also known as: Helmet, Sportsmatic

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

45mm

Case Thickness

9.4mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

50m

Dial Color

Black

Jewels

34j

Frequency

28,800 bph

Power Reserve

41 hours

Year

1998

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