In 1992, with the aim of creating a new benchmark of reliability and accuracy, the watchmakers chose their best movement: the Jaeger-LeCoultre 889 Calibre. They housed it in a case combining ruggedness and classic style and then subjected the watch to a battery of six stringent tests lasting 1000 hours, or nearly six weeks. The first Master Control was born. Since then, one by one, all round watches, followed then by other shapes of watch were optimised to reach the standard of performance demanded by the 1000 hour control. Today, every completed watch has to undergo this implacable series of tests before leaving the Manufacture.