The TimeWriter II Chronographe Bi-Fréquence 1000 measures and displays elapsed time to 1/1,000th of a second. Like many high-speed chronograph watches, it has a dual control system with two balance wheels – one for the time running at 2.5 hertz, and another one used for the chronograph, running at 50 Hz. Herein lies the magic: in order to measure 1/1000th of a second in the traditional way, the balance should actually be running at more like 500,000 Hz, or about 3.6-million vph. Instead, Montblanc, with the help of Spanish watchmaker Bartomeu Gomila, developed a system that divides each 1/100th of a second into subsets of 10 increments – in other words, the balance triggers a gear 100 times in each full turn rather than the usual two times. The chronograph function is controlled by a two-level column-wheel: one level guides the start, stop and zero-return functions; the other level controls the thousandths wheel.