Seiko Cal. 6644 - 678

This Spring Drive model from 1973 features a 39mm Titanium case. Powered by the 6644 caliber with 20j jewels beating at 21,600 bph, it delivers a 70 hours power reserve. [seikata-wm-286518867c83]

Also known as: Sumo

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

39mm

Case Thickness

10.3mm

Lug Width

19mm

Crystal

Mineral

Bezel

Rotating

Water Resistance

140m

Dial Color

Green

Jewels

20j

Frequency

21,600 bph

Power Reserve

70 hours

Year

1973

Related Models

• Seiko 3829-918
• Seiko 0733-177
• Seiko 0718-853
• Seiko 7062-199
• Seiko 4498-617
• Seiko 4567-650
• Seiko 3817-599
• Seiko 5276-858
• Seiko 4579-426
• Seiko 6343-291
• Seiko 4572-236
• Seiko 7168-462