Available exclusively in A. Lange & Söhne boutiques, this magnificent 40.5mm solid white gold Richard Lange comes with London certificate (Wempe's Old Bond Street Lange boutique), box and instruction booklets, and is in perfect unworn condition.

The Richard Lange is the first and only Lange & Söhne with sweep (centre) seconds. A descendant of the Lange survey chronometers used by polar expeditions in the early 1900s, the centre seconds layout allows high-precision reading. The in-house calibre L041.2 has a separate bridge over the three-quarter plate, which is part-functional (conveying the seconds drive) and part-flex (allowing Lange to display their skill at bevelling, with two beautiful razor-sharp hand-finished external corners).

Finely-frosted solid silver dial using an effect Lange calls argenté; the Arabic minutes round the outer edge are punctuated at the quarters in a discreet blue, matching the heat-blued steel alpha hands. Instant stop and start of the seconds by pulling the crown is not easy with such a relatively heavy hand, but Lange obtained this with a sprung linkage built into the small wheel train.

With Lange's well-deserved eminence in fine finishing, practical complications and tiny annual production, their watches are prized by collectors who appreciate exceptional value as well as technical mastery.