HYT bathes its H4 Metropolis in light - The Movie

The world's first watch dynamo converting mechanical power into light to read the time even in the dark. The generator has been nestled between 4 and 5 o'clock. It is invisible, and activated by the push-piece located opposite on the case middle. The process is broadly that of a dynamo: converting mechanical power into light energy. It is the rotation of the push-piece at 4:30 that winds the generator. Pressure on this same push-piece then activates the two LEDs which bathe the Metropolis in a soft blue light.