Seiko Cal. 6638 - 691

Released in 1970, the Cal. 6638 with design code 691 was part of Seiko's domestic market collection. With its 22mm lug width and 10.5mm profile, it sits comfortably on most wrists. [seikata-wm-29745ff276ff]

Also known as: Samurai, UFO

Specifications

Movement

Solar

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

10.5mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

100m

Dial Color

Green

Jewels

25j

Frequency

28,800 bph

Power Reserve

70 hours

Year

1970

Related Models

• Seiko 4537-297
• Seiko 7112-966
• Seiko 3829-276
• Seiko 6313-884
• Seiko 5638-195
• Seiko 3870-791
• Seiko 7135-993
• Seiko 5285-773
• Seiko 5283-566
• Seiko 6338-427
• Seiko 4560-781
• Seiko 5658-445