Seiko Cal. 6638 - 658

This Hand-Winding model from 1965 features a 41mm Hardlex-Coated Steel case. It features a Navy dial protected by a Hardlex crystal and offers 30m of water resistance. [seikata-wm-8aaddebd2aee]

Also known as: Helmet, Navigator

Specifications

Movement

Hand-Winding

Case Material

Hardlex-Coated Steel

Case Width

41mm

Case Thickness

12.8mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

30m

Dial Color

Navy

Jewels

25j

Frequency

36,000 bph

Power Reserve

47 hours

Year

1965

Related Models

• Seiko 4510-186
• Seiko 0756-782
• Seiko 4478-498
• Seiko 6118-797
• Seiko 6129-843
• Seiko 6131-997
• Seiko 0729-555
• Seiko 4481-561
• Seiko 5610-890
• Seiko 4525-466
• Seiko 6224-715
• Seiko 6382-722