Seiko Cal. 6638 - 257

The 6638-257 is a sought-after Spring Drive piece from Seiko's golden era. It features a Green dial protected by a Mineral crystal and offers 40m of water resistance. [seikata-wm-b58355b2323f]

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

35mm

Case Thickness

9.6mm

Lug Width

22mm

Crystal

Mineral

Bezel

Inner Rotating

Water Resistance

40m

Dial Color

Green

Jewels

36j

Frequency

28,800 bph

Power Reserve

39 hours

Year

1972

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