A stainless steel backed 10k gold filled Jaeger LeCoultre Powerwind watch. This handsome and quite rare piece was the first production watch to include a power reserve. Launched by Jaeger LeCoultre in 1948, they produced over one hundred thousand pieces. According to research into this model, nearly 75% of all Powerwind watches were exported to the US market for sale. Therefore most have this "LeCoultre" branding. There were a large number of dial variations, and case metals and sizes. However, this "Explorer" style dial layout remains quite rare. This watch is presented in superb, untouched condition. The eggshell coloured dial with applied metal makers also has lume plots applied to the outer minute track with small plot surrounds. Not many examples with luminous material applied to them, and this example also had lume applied to the hands from factory. The hand set is set off perfectly with a classic blued steel center sweep hand. This dial is signed "SWISS" just below the six o'clock lume plot marker. The watch is named for the curved aperture just below the 12 o'clock position. This indication disk displays from zero to forty hours, giving the wearer an understating of the approximate running time left in the movement. Hours zero to ten are displayed in red, giving clear indication that there is little power left in the movement. The movement inside this watch is the automatic, bumper wind caliber 481. This was the direct descendent of the caliber 476, which was jaeger's first bumper wind movement developed. It is a seventeen jewel 12 ligne movement, operating at eighteen thousnad beats per hour. The movement is equipped with Parachoc shock protection, Glucydur balance and a flat hairspring. This is a fine, and rare early example, with the case back serial number dating it circa early 1949. With this watch being introduced in 1948, this marks one of the very first examples. The screw back case is unpolished throughout, and with very few signs of wear. A superb watch that is easy to dress up or down, and represents a great addition to a large or blossoming collection.