Seiko Cal. 4540 - 639

The Seiko 4540-639 represents an important milestone in Seiko's 1969 lineup. The Bidirectional bezel and 37mm case give it a distinctive presence on the wrist. [seikata-wm-0de6d04b5f68]

Also known as: Bellmatic, Baby Tuna

Specifications

Movement

Quartz

Case Material

Gold-Plated

Case Width

37mm

Case Thickness

10.0mm

Lug Width

21mm

Crystal

Mineral

Bezel

Bidirectional

Water Resistance

30m

Dial Color

Navy

Jewels

18j

Frequency

28,800 bph

Power Reserve

41 hours

Year

1969

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