Seiko Cal. 6640 - 520

The Seiko 6640-520 represents an important milestone in Seiko's 1965 lineup. It features a Champagne dial protected by a Acrylic crystal and offers 170m of water resistance. [seikata-wm-4c1f7ea13a0e]

Also known as: UFO, Bellmatic

Specifications

Movement

Solar

Case Material

Hardlex-Coated Steel

Case Width

44mm

Case Thickness

10.3mm

Lug Width

22mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

170m

Dial Color

Champagne

Jewels

23j

Frequency

21,600 bph

Power Reserve

58 hours

Year

1965

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