Seiko Cal. 4550 - 728

The Seiko 4550-728 represents an important milestone in Seiko's 1981 lineup. It features a Black dial protected by a Hardlex crystal and offers 40m of water resistance. [seikata-wm-50d2d87ada78]

Also known as: Monster, Sumo

Specifications

Movement

Solar

Case Material

Hardlex-Coated Steel

Case Width

39mm

Case Thickness

15.2mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

40m

Dial Color

Black

Jewels

28j

Frequency

28,800 bph

Power Reserve

55 hours

Year

1981

Related Models

• Seiko 7121-165
• Seiko 6172-905
• Seiko 6299-560
• Seiko 6625-589
• Seiko 5249-204
• Seiko 3830-559
• Seiko 7077-145
• Seiko 4451-224
• Seiko 3884-196
• Seiko 6289-523
• Seiko 4495-528
• Seiko 4563-322