Seiko Cal. 3840 - 905

The Seiko 3840-905 represents an important milestone in Seiko's 1971 lineup. The Rotating bezel and 40mm case give it a distinctive presence on the wrist. [seikata-wm-38306023c6c6]

Also known as: Tuna

Specifications

Movement

Hand-Winding

Case Material

Hardlex-Coated Steel

Case Width

40mm

Case Thickness

11.6mm

Lug Width

19mm

Crystal

Acrylic

Bezel

Rotating

Water Resistance

150m

Dial Color

Navy

Jewels

32j

Frequency

36,000 bph

Power Reserve

37 hours

Year

1971

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