Seiko Cal. 5631 - 398

This Automatic model from 1981 features a 41mm Titanium case. With its 21mm lug width and 11.9mm profile, it sits comfortably on most wrists. [seikata-wm-f44b693e6c56]

Also known as: Tuna, Rally

Specifications

Movement

Automatic

Case Material

Titanium

Case Width

41mm

Case Thickness

11.9mm

Lug Width

21mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

130m

Dial Color

Cream

Jewels

32j

Frequency

36,000 bph

Power Reserve

40 hours

Year

1981

Related Models

• Seiko 4499-864
• Seiko 4513-805
• Seiko 7075-362
• Seiko 3899-909
• Seiko 6282-776
• Seiko 6161-723
• Seiko 0724-456
• Seiko 6399-467
• Seiko 7160-807
• Seiko 6388-434
• Seiko 5633-902
• Seiko 7120-682