Seiko Cal. 6640 - 243

The 6640-243 is a sought-after Spring Drive piece from Seiko's golden era. It features a Navy dial protected by a Acrylic crystal and offers 130m of water resistance. [seikata-wm-b3e683926d9a]

Also known as: Monster, Baby Tuna

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

37mm

Case Thickness

10.1mm

Lug Width

21mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

130m

Dial Color

Navy

Jewels

31j

Frequency

28,800 bph

Power Reserve

40 hours

Year

1980

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