Seiko Cal. 6631 - 788

This Spring Drive model from 1975 features a 39mm Two-Tone case. It features a White dial protected by a Mineral crystal and offers 150m of water resistance. [seikata-wm-46fc70a9c586]

Also known as: Tuna

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

39mm

Case Thickness

13.4mm

Lug Width

22mm

Crystal

Mineral

Bezel

Bidirectional

Water Resistance

150m

Dial Color

White

Jewels

34j

Frequency

28,800 bph

Power Reserve

59 hours

Year

1975

Related Models

• Seiko 6258-482
• Seiko 5294-554
• Seiko 4428-184
• Seiko 7127-489
• Seiko 7028-407
• Seiko 5289-611
• Seiko 6139-954
• Seiko 6134-678
• Seiko 7020-290
• Seiko 3859-405
• Seiko 7033-323
• Seiko 6361-244