Seiko Cal. 3866 - 821

The 3866-821 is a sought-after Hand-Winding piece from Seiko's golden era. Powered by the 3866 caliber with 30j jewels beating at 28,800 bph, it delivers a 49 hours power reserve. [seikata-wm-be2e051cb600]

Also known as: Bullhead, Sportsmatic

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

36mm

Case Thickness

15.2mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

140m

Dial Color

Silver

Jewels

30j

Frequency

28,800 bph

Power Reserve

49 hours

Year

1974

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