Seiko Cal. 6640 - 791

The Seiko 6640-791 represents an important milestone in Seiko's 1978 lineup. With its 21mm lug width and 11.3mm profile, it sits comfortably on most wrists. [seikata-wm-7c24f4176350]

Also known as: Crown, Flighty

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

40mm

Case Thickness

11.3mm

Lug Width

21mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

90m

Dial Color

Cream

Jewels

24j

Frequency

28,800 bph

Power Reserve

46 hours

Year

1978

Related Models

• Seiko 5683-417
• Seiko 5235-495
• Seiko 4593-778
• Seiko 6178-926
• Seiko 4515-254
• Seiko 6281-420
• Seiko 0775-946
• Seiko 6162-501
• Seiko 0717-178
• Seiko 6124-508
• Seiko 6180-263
• Seiko 6256-173