Seiko Cal. 4420 - 644

The 4420-644 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 4420 caliber with 24j jewels beating at 21,600 bph, it delivers a 70 hours power reserve. [seikata-wm-c3878fd7250f]

Also known as: Helmet

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

35mm

Case Thickness

11.0mm

Lug Width

22mm

Crystal

Mineral

Bezel

Inner Rotating

Water Resistance

160m

Dial Color

Navy

Jewels

24j

Frequency

21,600 bph

Power Reserve

70 hours

Year

1967

Related Models

• Seiko 6237-196
• Seiko 4520-710
• Seiko 0719-971
• Seiko 5256-385
• Seiko 6681-674
• Seiko 6694-561
• Seiko 7022-852
• Seiko 5640-966
• Seiko 7192-683
• Seiko 7051-101
• Seiko 6191-857
• Seiko 0722-274