Seiko Cal. 6640 - 888

This Spring Drive model from 1976 features a 34mm Titanium case. Powered by the 6640 caliber with 21j jewels beating at 36,000 bph, it delivers a 50 hours power reserve. [seikata-wm-165c305830c2]

Also known as: Bullhead, Baby Tuna

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

34mm

Case Thickness

15.9mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

70m

Dial Color

Navy

Jewels

21j

Frequency

36,000 bph

Power Reserve

50 hours

Year

1976

Related Models

• Seiko 0732-183
• Seiko 6116-901
• Seiko 0773-361
• Seiko 6231-308
• Seiko 6215-375
• Seiko 6326-969
• Seiko 5622-478
• Seiko 6155-937
• Seiko 6665-272
• Seiko 4596-858
• Seiko 4571-429
• Seiko 4568-906