Seiko Cal. 3840 - 978

The Seiko 3840-978 represents an important milestone in Seiko's 1977 lineup. The Coin-Edge bezel and 46mm case give it a distinctive presence on the wrist. [seikata-wm-1e42321339ad]

Also known as: Baby Tuna

Specifications

Movement

Kinetic

Case Material

PVD Black

Case Width

46mm

Case Thickness

8.6mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

40m

Dial Color

Green

Jewels

31j

Frequency

28,800 bph

Power Reserve

40 hours

Year

1977

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