Seiko Cal. 6637 - 420

The Seiko 6637-420 represents an important milestone in Seiko's 1982 lineup. The Inner Rotating bezel and 38mm case give it a distinctive presence on the wrist. [seikata-wm-47e3682c3030]

Also known as: Rally, Sportsmatic

Specifications

Movement

Solar

Case Material

PVD Black

Case Width

38mm

Case Thickness

12.2mm

Lug Width

19mm

Crystal

Mineral

Bezel

Inner Rotating

Water Resistance

170m

Dial Color

Green

Jewels

26j

Frequency

36,000 bph

Power Reserve

63 hours

Year

1982

Related Models

• Seiko 7175-714
• Seiko 4422-554
• Seiko 3871-321
• Seiko 5238-312
• Seiko 6243-489
• Seiko 5619-955
• Seiko 5280-706
• Seiko 3888-281
• Seiko 6647-856
• Seiko 6327-910
• Seiko 7016-875
• Seiko 6253-216