Seiko Cal. 6637 - 280

The Seiko 6637-280 represents an important milestone in Seiko's 1975 lineup. Powered by the 6637 caliber with 24j jewels beating at 28,800 bph, it delivers a 58 hours power reserve. [seikata-wm-06495836a667]

Also known as: Sumo, Tuna

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

42mm

Case Thickness

14.0mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

80m

Dial Color

Green

Jewels

24j

Frequency

28,800 bph

Power Reserve

58 hours

Year

1975

Related Models

• Seiko 0716-564
• Seiko 6352-787
• Seiko 5638-568
• Seiko 0796-191
• Seiko 5691-467
• Seiko 4465-955
• Seiko 5626-361
• Seiko 4433-588
• Seiko 7187-907
• Seiko 0794-977
• Seiko 7194-528
• Seiko 0763-954