Seiko Cal. 5640 - 721

Released in 1965, the Cal. 5640 with design code 721 was part of Seiko's domestic market collection. It features a Burgundy dial protected by a Sapphire crystal and offers 50m of water resistance. [seikata-wm-390e3cd1ef5e]

Also known as: Sumo, Navigator

Specifications

Movement

Kinetic

Case Material

Two-Tone

Case Width

43mm

Case Thickness

12.2mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

50m

Dial Color

Burgundy

Jewels

35j

Frequency

36,000 bph

Power Reserve

53 hours

Year

1965

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