This A. Lange and Sohne Datograph reference 403.032 is the chronograph that fixed the modern form of the genre. Lange's first chronograph paired a flyback function with the outsize date that became one of the firm's signatures, and for a collector of late twentieth-century watchmaking that alone gives it a central place. Its manual-wind caliber L951.1 remains the point, built on a column wheel architecture whose depth and finish are as admired as its operation. Rose gold gives the 39mm case a warmer reading than platinum, while 12.8mm of thickness keeps the watch compact rather than slight. On the dial, silver is the most restrained setting for the Datograph's applied Roman numerals and stepped registers. What followed at Lange grew larger, but many collectors still come back to this first Datograph for its tighter proportions and denser movement, a watch that did not just announce a complication but reestablished German watchmaking at the highest level.