Seiko Cal. 6640 - 894

The Seiko 6640-894 represents an important milestone in Seiko's 1987 lineup. Powered by the 6640 caliber with 23j jewels beating at 21,600 bph, it delivers a 56 hours power reserve. [seikata-wm-e37dee8eaa88]

Also known as: Golden Tuna

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

38mm

Case Thickness

15.1mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

150m

Dial Color

Green

Jewels

23j

Frequency

21,600 bph

Power Reserve

56 hours

Year

1987

Related Models

• Seiko 6189-825
• Seiko 4473-237
• Seiko 6674-478
• Seiko 7098-442
• Seiko 7065-714
• Seiko 6155-331
• Seiko 0711-118
• Seiko 4546-828
• Seiko 4596-387
• Seiko 4416-454
• Seiko 5253-723
• Seiko 7161-526