The A. Lange & Söhne Lange 1 Tourbillon Perpetual Calendar Lumen, ref. 720.035FE, is a limited platinum version of the brand’s top Lange 1 complication. The 950 platinum case is 41.9 mm in diameter and 13 mm thick, with 30 m water resistance and a black alligator strap with a folding buckle. The dial is grey-tinted, partly transparent sapphire. It shows the movement. The outsize date discs, leap-year indicator, moon phase, month ring, Roman numerals and hands all glow in the dark. The automatic calibre L225.1 has 685 components and 74 jewels, beats at 21,600 vph (3 Hz) and has a power reserve of up to 50 hours. It has a one-minute tourbillon with stop-seconds, mounted on the back of the movement. The perpetual calendar shows the month on a ring around the dial edge, the day in a retrograde display, the leap year at 6 o’clock and the moon phase with a day/night indicator in the small seconds subdial. If the watch runs continuously, it needs no correction until 1 March 2100.

The watch was launched at Watches and Wonders 2026. It belongs to Lange’s Lumen series of semi-transparent luminous dials, which also includes the Grand Lange 1 Lumen of 2012 and the Datograph Lumen of 2018. Compared with the earlier movement, the L225.1 adds the day/night display and a reworked going train. Its rotor is 18 ct white gold plated with black rhodium, a first for Lange, with a platinum rim. The tourbillon cock and intermediate-wheel cock are black-polished steel engraved with stars, and the tourbillon cock also has a shooting star. Production is limited to 50 pieces. The price is EUR 550,000 according to aBlogtoWatch and USD 530,000 according to WatchesBySJX.

WatchesBySJX ranked it among the most appealing Lumen models, alongside the original Zeitwerk “Phantom”. It praised the luminous numeral bases, the engraved steel cocks, the instantaneous calendar and the decoration. It marked the watch down for originality and said the movement is arguably still a variant of the first generation. aBlogtoWatch called the calendar layout one of the most logical and legible designs and noted the surprise of the tourbillon on the back. It also said the transparency comes at a high price. As of October 2026, it is a current limited edition of 50 pieces.