A. LANGE & SÖHNE fine & rare 18k yellow gold Tourbillon Pour le Mérite, reference 701.001, mad one a limited special edition of 150 pieces, 3-piece construction case including leather strap with original 18k yellow gold deployant clasp, on both sides sapphire glazed, case back 6-times screwed, frosted silvered dial with Arabic hours, visible one- minute tourbillon under polished steel bridge to view the tourbillon cage at 6, blued Alpha steel hands, display of hours, minutes, constant second at 3 & power reserve indicatorat 9, fine, rhodium plated board movement, calibre L902.2, 29 jewels, 29 jewels thereof 5 in screwed down gold chatons, powered by chain & fusee, tourbillon cage bearing 2 diamond end stones, glucydur-screw-balance, Breguet-hairspring, hand engraved balance cock, diameter approx. 38,5 mm, original box & papers, sold in October 1997, additional certificate of origin made by A. Lange & Söhne from August 2019 enclosed, condition 2, property of a collector