A ref. 405.034 Datograph Up/Down Lumen, the fourth Lumen model and only pure chronograph expression of Lange's Lumen treatment. This Datograph features a smoked sapphire dial which limits light yet allows UV to charge elements beneath. At night, the tachymeter & minute scales, grande date, handset, and power reserve are all luminous in a muted glowing green. By day, drama is still present through dial-side pelage and the immense beauty of A. Lange & Söhne's architectural calibre L951.7. The 405.034 was made in a limited numbered production of 200 examples.