http://www.lussori.com/blancpain-spe...gmt-watch.html
The Blancpain Specialites GMT is animated by the selfwinding 5A50 Calibre, which offers the impressive power-reserve of 100 hours, when fully wound. It features a mechanism that allows the 12-hour hand to be adjusted in hourly leaps, without any disturbance to the second hand or minute hand; the date display is also linked to this hand, and it can be adjusted backward as well as forwards. In conjunction with the supplementary red 24-hour hand and the 24 hour rotating bezel, this enables the world traveler to make adjustments to his watch at an arrival in each new timezone without disturbing the accuracy of the watch; at the same time, the red hand and bezel can keep track of the time in two additional timezones of choice.
The 5A50 Calibre is made up of 238 hand-finished pieces, and each individual movement is built and fine-tuned by a single Blancpain watchmaker; the bridges and winding rotor are decorated with Cotes de Geneve, while the plates are adorned with perlage. Screws are individually polished to a mirror finish, and all edges are rounded with anglage. Traditionally, such finishes do serve functional purposes, but they also reflect the great pride in the craft of traditional watchmaking that is cultivated in the Blancpain atelier.