Seiko Cal. 4521 - 378

The 4521-378 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 4521 caliber with 27j jewels beating at 36,000 bph, it delivers a 44 hours power reserve. [seikata-wm-dc4fb796ea7d]

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

14.7mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

170m

Dial Color

Silver

Jewels

27j

Frequency

36,000 bph

Power Reserve

44 hours

Year

1974

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