Seiko Cal. 6640 - 544

The Seiko 6640-544 represents an important milestone in Seiko's 1996 lineup. Powered by the 6640 caliber with 28j jewels beating at 36,000 bph, it delivers a 47 hours power reserve. [seikata-wm-a974a2287c7c]

Also known as: Bullhead, Emperor

Specifications

Movement

Quartz

Case Material

Titanium

Case Width

35mm

Case Thickness

14.2mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Bidirectional

Water Resistance

160m

Dial Color

Blue Sunburst

Jewels

28j

Frequency

36,000 bph

Power Reserve

47 hours

Year

1996

Related Models

• Seiko 6141-238
• Seiko 6343-592
• Seiko 5694-208
• Seiko 6110-131
• Seiko 6240-604
• Seiko 0710-346
• Seiko 7097-329
• Seiko 5628-244
• Seiko 0738-861
• Seiko 6615-388
• Seiko 6232-998
• Seiko 5297-630