Rare Swiss sterling silver chronometer pocket watch Circa 1965

Sterling silver precision watch
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A very rare, early version Swiss sterling silver open faced observation chronometer with 48 hour power reserve made by Zenith S.A., circa 1965. The ½ plate movement with a piston tooth lever escapement and an extremely large Glucydur balance. White enamel dial with Roman hour numerals, an outer minute track, power reserve indication at 12 o’clock, sunk subsidiary seconds at 6 and blued hands. The case with plain bezels, band, pendant and bow, and an engine turned back. Dial signed, case numbered, movement numbered and signed.
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Diameter: 60 mm
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Weight: 194 g
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Signed: Zenith Chronomètre Swiss made
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The Zenith caliber 5011K movement was originally introduced in 1960. It was considered the most precise movement in its category and is probably one of the best movements ever made.