Seiko Cal. 7031 - 637

The 7031-637 is a sought-after Hand-Winding piece from Seiko's golden era. With its 18mm lug width and 10.9mm profile, it sits comfortably on most wrists. [seikata-wm-5a499651abdc]

Also known as: Tuna, UFO

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

40mm

Case Thickness

10.9mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

90m

Dial Color

Navy

Jewels

22j

Frequency

21,600 bph

Power Reserve

38 hours

Year

1965

Related Models

• Seiko 5652-188
• Seiko 3881-256
• Seiko 4599-669
• Seiko 7195-760
• Seiko 6146-640
• Seiko 7137-623
• Seiko 7150-445
• Seiko 0744-458
• Seiko 7056-764
• Seiko 6681-191
• Seiko 7163-365
• Seiko 6397-580