Seiko Cal. 5638 - 647

This Quartz model from 1986 features a 45mm Hardlex-Coated Steel case. With its 21mm lug width and 15.7mm profile, it sits comfortably on most wrists. [seikata-wm-944c3da99397]

Also known as: Sumo, UFO

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

45mm

Case Thickness

15.7mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

40m

Dial Color

Burgundy

Jewels

27j

Frequency

36,000 bph

Power Reserve

65 hours

Year

1986

Related Models

• Seiko 5645-458
• Seiko 3882-217
• Seiko 4593-547
• Seiko 3858-806
• Seiko 5255-517
• Seiko 3865-822
• Seiko 5671-155
• Seiko 6242-744
• Seiko 4593-789
• Seiko 6223-231
• Seiko 6168-953
• Seiko 4472-856