As to the springs, a Rolex communication titled Parachrom Hairspring dated 08/12/06 given to representatives at a factory tour in Geneva explains:
"Rolex has developed and patented a new hairspring called PARACHROM. This hairspring is made of a niobium, zirconium and oxygen alloy. It has been used for the Cosmograph Daytona starting from 2000. In 2005 a blue-coloured version was introduced for the new GMT Master II and the Cosmograph Daytona. It has an even better performance as regards to long-term stability. This blue version has also been patented. The hairspring and balance form an oscillator, the regulating organ of the watch. This oscillator is the guardian of time. The precision of the watch is determined by the regularity of its oscillations. The requirements of this regularity are very great since measuring the time with a precision of 1 second per d ay is like measuring a distance of 1 km to within 1 cm. To guarantee this extreme precision, the torque must be as constant as possible regardless of the temperature to which the watch is submitted. It is for this reason that only a few, very special materials can be used for the hairspring.
