The A. Lange & Söhne 1815 Chronograph Boutique Edition reference 410.026 is a special edition of the 2010 1815 Chronograph only available in the 15 A. Lange & Söhne boutiques. It features a white gold case and a grained silver dial with blue numerals. As are the other 1815 Chronographs of this generation, this watch is powered by the L951.5 caliber.