Seiko Cal. 5640 - 437

The Seiko 5640-437 represents an important milestone in Seiko's 1993 lineup. It features a Black dial protected by a Sapphire crystal and offers 170m of water resistance. [seikata-wm-0af1878a453f]

Also known as: World Timer

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

42mm

Case Thickness

8.5mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

170m

Dial Color

Black

Jewels

21j

Frequency

28,800 bph

Power Reserve

44 hours

Year

1993

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