Seiko Cal. 6640 - 723

This Automatic model from 1970 features a 38mm Two-Tone case. Powered by the 6640 caliber with 36j jewels beating at 21,600 bph, it delivers a 65 hours power reserve. [seikata-wm-77ab33d31610]

Also known as: Helmet, World Timer

Specifications

Movement

Automatic

Case Material

Two-Tone

Case Width

38mm

Case Thickness

12.2mm

Lug Width

21mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

160m

Dial Color

Blue Sunburst

Jewels

36j

Frequency

21,600 bph

Power Reserve

65 hours

Year

1970

Related Models

• Seiko 6372-392
• Seiko 7195-547
• Seiko 6353-290
• Seiko 6284-137
• Seiko 7197-825
• Seiko 4536-954
• Seiko 0762-526
• Seiko 6318-581
• Seiko 4479-695
• Seiko 7010-132
• Seiko 6343-263
• Seiko 6363-410