Seiko Cal. 4521 - 957

This Spring Drive model from 1968 features a 40mm Stainless Steel case. Powered by the 4521 caliber with 23j jewels beating at 28,800 bph, it delivers a 36 hours power reserve. [seikata-wm-f95f73d9af8d]

Also known as: Baby Tuna

Specifications

Movement

Spring Drive

Case Material

Stainless Steel

Case Width

40mm

Case Thickness

15.3mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

120m

Dial Color

Burgundy

Jewels

23j

Frequency

28,800 bph

Power Reserve

36 hours

Year

1968

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