Seiko Cal. 3870 - 521

The 3870-521 is a sought-after Hand-Winding piece from Seiko's golden era. Powered by the 3870 caliber with 31j jewels beating at 21,600 bph, it delivers a 59 hours power reserve. [seikata-wm-28c1c7243830]

Also known as: Sea Horse, Flighty

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

39mm

Case Thickness

12.4mm

Lug Width

18mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

100m

Dial Color

White

Jewels

31j

Frequency

21,600 bph

Power Reserve

59 hours

Year

1977

Related Models

• Seiko 7186-439
• Seiko 5672-985
• Seiko 6211-671
• Seiko 6271-360
• Seiko 5259-761
• Seiko 5224-377
• Seiko 4489-852
• Seiko 0797-519
• Seiko 6615-254
• Seiko 5654-849
• Seiko 6362-585
• Seiko 3822-643