Seiko Cal. 3840 - 648

The Seiko 3840-648 represents an important milestone in Seiko's 1971 lineup. The Bidirectional bezel and 39mm case give it a distinctive presence on the wrist. [seikata-wm-4d407ca00b72]

Also known as: Baby Tuna

Specifications

Movement

Spring Drive

Case Material

Gold-Plated

Case Width

39mm

Case Thickness

13.7mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

30m

Dial Color

Green

Jewels

21j

Frequency

28,800 bph

Power Reserve

54 hours

Year

1971

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