Seiko Cal. 6631 - 818

The Seiko 6631-818 represents an important milestone in Seiko's 1972 lineup. Powered by the 6631 caliber with 17j jewels beating at 36,000 bph, it delivers a 49 hours power reserve. [seikata-wm-31eb0e30b22a]

Also known as: Golden Tuna

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

43mm

Case Thickness

14.4mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

190m

Dial Color

Silver

Jewels

17j

Frequency

36,000 bph

Power Reserve

49 hours

Year

1972

Related Models

• Seiko 0746-277
• Seiko 7079-270
• Seiko 3863-375
• Seiko 6194-114
• Seiko 5618-596
• Seiko 5250-162
• Seiko 5271-815
• Seiko 4540-211
• Seiko 7141-388
• Seiko 4533-370
• Seiko 6620-513
• Seiko 0725-995