With A. Lange & Söhne Guarantee Certificate dated 1999, original sales tag, instruction manual, copy of Wempe servicing invoice dated 2005, two spare bracelets, spare 18K gold deployant clasp, original fitted presentation box and outer packaging.
Since its overhaul in 2005, the present watch has not been used and is preserved in like new condition. This coveted collector's wristwatch is number 107 of a strictly limited edition of 150 examples of the Tourbillon "Pour le Mérite" model in gold. In production from 1994 until 1998, the series included 15 examples in pink gold with black dial, such as this watch, 15 examples in white gold and 120 examples in yellow gold. The limited edition furthermore comprised 50 examples cased in platinum.
The Tourbillon "Pour le Mérite", another example of A. Lange & Söhne's complex and exclusive timepieces, incorporates a number of fascinating technical details never seen before in a wristwatch, most notably the going train driven with a chain fusée. This complicated mechanism optimises the rate accuracy of the watch and is visible through an aperture in the movement plate. A highly sophisticated planetary gearing system keeps the power to the going train steady even while the watch is being wound.
The tourbillon mechanism also serves the purpose of improving rate accuracy by offsetting the disruptive effect of gravity. The rotating cage is suspended by two pivots between two diamond endstones. It turns around its own axis once a minute and can be precisely balanced with small counterweights.
All parts of the watch are finished by hand and every surface is decorated. Consequently, the completion of each of these masterpieces requires several months.
It is commonly believed that the Tourbillon "Pour le Mérite" is one of only two wristwatches known to date fitted with a chain and fusée for the power equalization. The second model is its even more complicated successor, the Tourbograph "Pour le Mérite" combining a tourbillon and a split seconds chronograph mechanism, introduced into the market in 2006.
The Tourbograph "Pour le Mérite" no. 24/51 in platinum, consigned by the same distinguished private collector, will be offered at Christie's Hong Kong "Important Watches" auction on 2 December 2009.