This is A. Lange & Sohne Double Split in platinum. The watch's 43mm case features an exquisite round bezel made of platinum. Its strap is made from black crocodile leather and has a platinum tang buckle.. The watch's hours, minutes, split seconds, double rattrapante, flyback chronograph and tachymeter functions are displayed on a black dial and powered by the watch's Calibre L001.1 manual winding movement with ~38 hours power reserve. The movement's intriguing vibrations can be viewed via the watch's transparent sapphire crystal case back.