The Zeitwerk Honeygold “Lumen” is a wristwatch by A. Lange & Söhne.

Presented in 2021, the name of this model in the Zeitwerk series refers to the Lange-exclusive case material Honeygold, which is a warmer gold hue, and to the translucent coating of the dial, which allows the luminous numerals that are not exposed in the aperture to absorb enough UV light, and thus light energy needed to make them glow in the dark. The digital display can therefore also be read immediately after each switching operation. At night, the numerals, which are only dimly visible during the day, allow the watch to glow.

The watch is powered by the hand-wound manufacture caliber L043.9, whose mechanism simultaneously advances all three dials by one counter on the hour. The patented constant-force escapement handles two important functions: on the one hand, it generates the impulse for the abrupt advance of the time display. Second, it drives the balance over the entire running time with almost constant energy.