According to the Archives of Jaeger-LeCoultre, the present Beaubourg Phases de Lune desk clock was delivered on 15 June 1998.

It features a 24K gold-plated moon phase display, which, once correctly set, will need adjustment only after 600 years. The spirit level in the round aperture underneath the balance allows correct adjustment of the feet, by turning the two screws to each side until the indication correctly adjusted.

Jean-Léon Reutter invented the first prototype of an Atmos clock in 1928, since 1935 it has been commercialized and improved by Jaeger-LeCoultre. To achieve the concept of eternal motion, the clock derives its energy from the expansion and contraction of a capsule that includes a mixture of gas and liquid that responds to changes in barometric pressure. When the capsule is connected to the mechanism of the watch, temperature fluctuations constantly drive the movement without the need for manual mounting.