The Datograph Perpetual Tourbillon Honeygold Lumen, reference 740.055FE, combines a flyback chronograph with a jumping minute counter, a perpetual calendar with moon phase, an outsize date, a day/night indicator and a one-minute tourbillon with stop-seconds. The case is made of Honeygold, a gold alloy exclusive to Lange that is harder than conventional 18k gold. It measures 41.5 mm in diameter and 14.6 mm in height, with a sapphire crystal, a sapphire case back and 3 bar of water resistance. The semi-transparent dial is made of smoked sapphire crystal, which lets ultraviolet light reach the luminous elements so the displays glow in the dark. The hand-wound calibre L952.4 has 684 parts, beats at 18,000 semi-oscillations per hour (2.5 Hz) and has a 50-hour power reserve.

Lange presented the watch at Watches and Wonders in April 2024 to mark 25 years of the Datograph. It joins the Lumen series, which uses partially tinted sapphire dials and luminous compound, and follows the Datograph Perpetual Tourbillon that debuted in platinum in 2016. According to Watches by SJX, calibre L952.4 differs from the standard L952.2 mainly by omitting the power reserve indicator, and the perpetual calendar is integrated into the dial side of the mainplate. The watch comes on a dark brown alligator strap with a Honeygold deployant clasp. Production is limited to 50 pieces sold through Lange boutiques. Lange lists the price on request, and SJX estimated it at around EUR 620,000 including VAT.

Press coverage centred on how the Lumen treatment exposes the movement and calendar mechanics through the dial. Watches by SJX called the watch nearly faultless and described the base L951 chronograph as best-in-class after 25 years. The same review said the watch combines known elements rather than breaking new ground and that it had expected more from Lange. It also noted the case is somewhat top-heavy, though acceptable for the level of complication. Fratello and Monochrome covered it as the highlight of Lange’s Datograph anniversary, and Watchilove’s hands-on praised the Honeygold case and the feel of the pushers. As of October 2026 it remains a limited edition of 50 pieces, with the price available only on request.