Seiko Cal. 4540 - 181

Released in 1981, the Cal. 4540 with design code 181 was part of Seiko's domestic market collection. The Inner Rotating bezel and 37mm case give it a distinctive presence on the wrist. [seikata-wm-9604ee8ae2a9]

Also known as: Bullhead, UFO

Specifications

Movement

Automatic

Case Material

Two-Tone

Case Width

37mm

Case Thickness

8.3mm

Lug Width

18mm

Crystal

Mineral

Bezel

Inner Rotating

Water Resistance

140m

Dial Color

Black

Jewels

30j

Frequency

36,000 bph

Power Reserve

72 hours

Year

1981

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