Seiko Cal. 6640 - 837

This Spring Drive model from 1985 features a 37mm Two-Tone case. It features a Navy dial protected by a Hardlex crystal and offers 50m of water resistance. [seikata-wm-ac3e2195f048]

Also known as: Rally, Sportsmatic

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

37mm

Case Thickness

10.0mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

50m

Dial Color

Navy

Jewels

18j

Frequency

28,800 bph

Power Reserve

38 hours

Year

1985

Related Models

• Seiko 6251-893
• Seiko 7149-363
• Seiko 5262-757
• Seiko 6390-132
• Seiko 4530-303
• Seiko 3895-203
• Seiko 6394-362
• Seiko 7196-888
• Seiko 5664-135
• Seiko 7141-636
• Seiko 4490-921
• Seiko 5691-610