Seiko Cal. 4420 - 731

The Seiko 4420-731 represents an important milestone in Seiko's 1987 lineup. It features a Navy dial protected by a Hardlex crystal and offers 170m of water resistance. [seikata-wm-52653dd9c28f]

Also known as: Sumo

Specifications

Movement

Quartz

Case Material

Stainless Steel

Case Width

36mm

Case Thickness

15.4mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Coin-Edge

Water Resistance

170m

Dial Color

Navy

Jewels

25j

Frequency

36,000 bph

Power Reserve

46 hours

Year

1987

Related Models

• Seiko 6367-980
• Seiko 4469-116
• Seiko 3837-829
• Seiko 6357-371
• Seiko 7178-426
• Seiko 7135-468
• Seiko 5256-140
• Seiko 4543-503
• Seiko 5673-181
• Seiko 3861-322
• Seiko 6244-276
• Seiko 5619-897