Seiko Cal. 4528 - 721

The Seiko 4528-721 represents an important milestone in Seiko's 1977 lineup. Powered by the 4528 caliber with 18j jewels beating at 28,800 bph, it delivers a 72 hours power reserve. [seikata-wm-0d3ff77e365d]

Also known as: Helmet, Bellmatic

Specifications

Movement

Solar

Case Material

Hardlex-Coated Steel

Case Width

35mm

Case Thickness

9.7mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

180m

Dial Color

Cream

Jewels

18j

Frequency

28,800 bph

Power Reserve

72 hours

Year

1977

Related Models

• Seiko 3812-328
• Seiko 7082-384
• Seiko 5652-188
• Seiko 6369-792
• Seiko 6397-582
• Seiko 7152-232
• Seiko 5275-432
• Seiko 6341-696
• Seiko 6364-158
• Seiko 6190-584
• Seiko 7037-836
• Seiko 5637-959