Seiko Cal. 3878 - 991

The Seiko 3878-991 represents an important milestone in Seiko's 1977 lineup. Powered by the 3878 caliber with 27j jewels beating at 36,000 bph, it delivers a 54 hours power reserve. [seikata-wm-4e6339e60324]

Also known as: Sumo, Baby Tuna

Specifications

Movement

Quartz

Case Material

PVD Black

Case Width

46mm

Case Thickness

8.5mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

80m

Dial Color

Burgundy

Jewels

27j

Frequency

36,000 bph

Power Reserve

54 hours

Year

1977

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