Seiko Cal. 5631 - 691

This Hand-Winding model from 1978 features a 35mm PVD Black case. With its 21mm lug width and 15.5mm profile, it sits comfortably on most wrists. [seikata-wm-d3218a4f2b1a]

Also known as: Rally, Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

PVD Black

Case Width

35mm

Case Thickness

15.5mm

Lug Width

21mm

Crystal

Acrylic

Bezel

Bidirectional

Water Resistance

180m

Dial Color

Navy

Jewels

31j

Frequency

21,600 bph

Power Reserve

52 hours

Year

1978

Related Models

• Seiko 0737-608
• Seiko 6348-383
• Seiko 4562-779
• Seiko 5638-280
• Seiko 6127-965
• Seiko 7161-466
• Seiko 7040-426
• Seiko 6113-405
• Seiko 4548-341
• Seiko 6375-916
• Seiko 7110-951
• Seiko 6259-714