Seiko Cal. 6640 - 256

The 6640-256 is a sought-after Hand-Winding piece from Seiko's golden era. It features a Black dial protected by a Mineral crystal and offers 150m of water resistance. [seikata-wm-c565642312ef]

Also known as: Helmet, Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

PVD Black

Case Width

35mm

Case Thickness

10.7mm

Lug Width

22mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

150m

Dial Color

Black

Jewels

36j

Frequency

36,000 bph

Power Reserve

48 hours

Year

1989

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