Seiko Cal. 6641 - 557

Released in 1986, the Cal. 6641 with design code 557 was part of Seiko's domestic market collection. The Fixed bezel and 45mm case give it a distinctive presence on the wrist. [seikata-wm-a6f6aa4fae70]

Also known as: Sumo, Helmet

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

45mm

Case Thickness

15.2mm

Lug Width

22mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

180m

Dial Color

Black

Jewels

29j

Frequency

21,600 bph

Power Reserve

48 hours

Year

1986

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