Seiko Cal. 6635 - 378

The Seiko 6635-378 represents an important milestone in Seiko's 1971 lineup. The Inner Rotating bezel and 42mm case give it a distinctive presence on the wrist. [seikata-wm-6a74b98abb55]

Also known as: Tuna

Specifications

Movement

Quartz

Case Material

Gold-Plated

Case Width

42mm

Case Thickness

9.8mm

Lug Width

22mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

150m

Dial Color

Blue Sunburst

Jewels

32j

Frequency

28,800 bph

Power Reserve

54 hours

Year

1971

Related Models

• Seiko 6174-283
• Seiko 3885-679
• Seiko 5685-560
• Seiko 5676-200
• Seiko 7110-248
• Seiko 7170-497
• Seiko 6214-697
• Seiko 4411-296
• Seiko 6369-933
• Seiko 6659-838
• Seiko 7074-174
• Seiko 3862-451