Seiko Cal. 6637 - 864

This Spring Drive model from 1981 features a 45mm Two-Tone case. The Coin-Edge bezel and 45mm case give it a distinctive presence on the wrist. [seikata-wm-dfa9fccc4173]

Also known as: Turtle, Tuna

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

45mm

Case Thickness

12.9mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

150m

Dial Color

Silver

Jewels

19j

Frequency

21,600 bph

Power Reserve

42 hours

Year

1981

Related Models

• Seiko 0729-231
• Seiko 3858-968
• Seiko 6255-820
• Seiko 7049-408
• Seiko 7026-682
• Seiko 5682-304
• Seiko 4554-206
• Seiko 6385-360
• Seiko 6312-296
• Seiko 7083-391
• Seiko 6652-885
• Seiko 0718-162