Seiko Cal. 5640 - 931

This Spring Drive model from 1975 features a 46mm Two-Tone case. It features a Green dial protected by a Sapphire crystal and offers 200m of water resistance. [seikata-wm-2b5489b40adb]

Also known as: Turtle

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

46mm

Case Thickness

8.6mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

200m

Dial Color

Green

Jewels

18j

Frequency

21,600 bph

Power Reserve

39 hours

Year

1975

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