The 850P, often called "the traveller’s movement" is a self-winding mechanical movement. Like its immediate predecessor, the 800P, it has a double barrel and offers three particularly useful functions for the contemporary traveller: second time zone, day/night indicator and date window at 12 o'clock. Its 12-hour time zone at 7 o'clock allows the setting of a second time, different from home time driven by the central movement. Inside this zone is the day/night indicator linked to the home time, telling the traveller whether the sun is shining in his home city. On the other side of the main dial, at 5 o'clock, a small seconds indication completes this ideal globe-trotter’s watch. Circular Côtes de Genève, a circular-grained mainplate, bevelled bridges, blued screws and an oscillating weight engraved with the Piaget coat-of-arms add the finishing touches to this movement and are reminders of the Swiss watchmaking brand's high aesthetic values.