Seiko Cal. 4520 - 639

This Spring Drive model from 1971 features a 37mm Titanium case. With its 18mm lug width and 15.1mm profile, it sits comfortably on most wrists. [seikata-wm-b4232095522d]

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

37mm

Case Thickness

15.1mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

200m

Dial Color

Blue Sunburst

Jewels

28j

Frequency

21,600 bph

Power Reserve

55 hours

Year

1971

Related Models

• Seiko 7080-158
• Seiko 7058-277
• Seiko 0785-221
• Seiko 0752-934
• Seiko 5634-684
• Seiko 7053-964
• Seiko 4550-395
• Seiko 7072-549
• Seiko 6132-871
• Seiko 6291-745
• Seiko 0778-382
• Seiko 5674-636