Seiko Cal. 5639 - 728

The 5639-728 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 5639 caliber with 20j jewels beating at 36,000 bph, it delivers a 38 hours power reserve. [seikata-wm-29201407278e]

Also known as: Tuna

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

43mm

Case Thickness

10.4mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

200m

Dial Color

Burgundy

Jewels

20j

Frequency

36,000 bph

Power Reserve

38 hours

Year

1972

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