Seiko Cal. 6631 - 394

The Seiko 6631-394 represents an important milestone in Seiko's 1998 lineup. With its 21mm lug width and 14.3mm profile, it sits comfortably on most wrists. [seikata-wm-fa55da175abc]

Also known as: Monster, Sportsmatic

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

37mm

Case Thickness

14.3mm

Lug Width

21mm

Crystal

Mineral

Bezel

Rotating

Water Resistance

100m

Dial Color

Black

Jewels

33j

Frequency

36,000 bph

Power Reserve

67 hours

Year

1998

Related Models

• Seiko 6640-676
• Seiko 6199-607
• Seiko 7190-737
• Seiko 4467-317
• Seiko 3891-131
• Seiko 7184-325
• Seiko 4536-580
• Seiko 5699-565
• Seiko 0795-224
• Seiko 4434-867
• Seiko 5268-235
• Seiko 6153-686