Seiko Cal. 6640 - 761

The Seiko 6640-761 represents an important milestone in Seiko's 1977 lineup. It features a White dial protected by a Sapphire crystal and offers 70m of water resistance. [seikata-wm-b7bf62b6d0ff]

Also known as: Bellmatic, Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

Gold-Plated

Case Width

35mm

Case Thickness

10.2mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

70m

Dial Color

White

Jewels

31j

Frequency

36,000 bph

Power Reserve

59 hours

Year

1977

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