Seiko Cal. 6618 - 631

The Seiko 6618-631 represents an important milestone in Seiko's 1988 lineup. Powered by the 6618 caliber with 33j jewels beating at 36,000 bph, it delivers a 68 hours power reserve. [seikata-wm-a701dba21670]

Also known as: Helmet, UFO

Specifications

Movement

Hand-Winding

Case Material

Stainless Steel

Case Width

37mm

Case Thickness

11.8mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

30m

Dial Color

Burgundy

Jewels

33j

Frequency

36,000 bph

Power Reserve

68 hours

Year

1988

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