Improve the performance and extend the life of your StopTech Power Slot rotors with the Cryo option. This one-time cryogenic treatment is a computer controlled process where the metal is cooled gradually to -300 degrees Fahrenheit and then slowly returned to room temperature and heat cycled as the final step. Although not apparent to the naked eye, the improvements to the rotor are significant. The cryogenic treatment process redistributes residual stress in the rotor giving it an extra level of protection against warping. Only new StopTech Power Slot rotors can be Cryo treated. Please only choose the Cryo option if you are purchasing a new set of rotors.