Seiko Cal. 5631 - 391

The Seiko 5631-391 represents an important milestone in Seiko's 1987 lineup. Powered by the 5631 caliber with 33j jewels beating at 28,800 bph, it delivers a 47 hours power reserve. [seikata-wm-c8cd2a195451]

Also known as: Turtle, Crown

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

36mm

Case Thickness

11.8mm

Lug Width

22mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

150m

Dial Color

White

Jewels

33j

Frequency

28,800 bph

Power Reserve

47 hours

Year

1987

Related Models

• Seiko 7066-270
• Seiko 7054-619
• Seiko 7110-260
• Seiko 6334-473
• Seiko 4587-640
• Seiko 0795-945
• Seiko 6213-914
• Seiko 6694-499
• Seiko 6194-866
• Seiko 5618-625
• Seiko 5222-961
• Seiko 4448-718