Swiss stainless steel staybrite chronograph Circa 1940

Stainless steel watch with register and tachometer
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A Swiss stainless steel keyless open faced pocket watch made by Rolex in Switzerland, circa 1940. Staybrite pocket watch with single button chronograph, register and tachometer. A polished plain case with a hinged cuvette. White enamel dial with Arabic hours, an outer minute track, outermost fifths of second divisions with Arabic numerals, subsidiary seconds at 6 o’clock, an instantaneous 30 minute register at 12 and blued steel spade hands. The movement has a lever escapement. Signature on the dial, case and movement.
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Diameter: 49 mm
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Weight: 63 g
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Signed: Rolex, Swiss made