A. Lange & Söhne caliber L903.0
Hand-wound movement introduced in celebration of the 15th anniversary of a. Lange & Söhne, featuring a tourbillon, chain & fusée and a flyback, rattrapante chronograph. The terminal curve of the balance spring is bent according to calculations made by Prof. Strasser of Glashütte. The 'Tourbograph' was originally conceived by Günter Blumlein, who sadly never got to see the final result. It consists of over 1000 individual parts.