Seiko Cal. 4438 - 366

This Spring Drive model from 1980 features a 37mm Two-Tone case. Powered by the 4438 caliber with 18j jewels beating at 21,600 bph, it delivers a 48 hours power reserve. [seikata-wm-9d86ac55439f]

Also known as: Bullhead, Sportsmatic

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

37mm

Case Thickness

11.0mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

120m

Dial Color

Green

Jewels

18j

Frequency

21,600 bph

Power Reserve

48 hours

Year

1980

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