Seiko Cal. 3870 - 647

The Seiko 3870-647 represents an important milestone in Seiko's 1982 lineup. The Coin-Edge bezel and 36mm case give it a distinctive presence on the wrist. [seikata-wm-cc5d80c88f25]

Also known as: Tuna, Helmet

Specifications

Movement

Kinetic

Case Material

PVD Black

Case Width

36mm

Case Thickness

11.4mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

50m

Dial Color

Blue Sunburst

Jewels

32j

Frequency

21,600 bph

Power Reserve

40 hours

Year

1982

Related Models

• Seiko 4514-993
• Seiko 5213-955
• Seiko 6183-713
• Seiko 7025-495
• Seiko 5686-347
• Seiko 3854-383
• Seiko 6617-657
• Seiko 6695-594
• Seiko 7060-860
• Seiko 6364-123
• Seiko 7162-272
• Seiko 5280-929