StopTech Sport Rotors are also available with an optional cryogenic treatment. Although cryogenic treatment is invisible to the naked eye, many fleet customers are sold on its ability to extend the service life of the brake rotor. Deep cryogenic treatment is a one-time process that permanently improves the performance and wear characteristics of metal components, from brake rotors and engine parts to machine tools and gear sets. All new StopTech Sport Rotors may be ordered with cryogenic treatment for an additional fee. Symmetric vane, split-core castings for uniform heat distribution. Black E-Coat anti-corrosive coating protects much better than competitors spray paint. Double disc ground friction surface for optimal performance and service life This extra process provides better rotor balance and creates a cleaner; more finished looking component; In addition; Rotors are inspected for balance and mill-corrected to a tolerance of less than 2oz 2005 - 2008 Infiniti G35, 2006 - 2009 Nissan 350Z, 2006 - 2010 Infiniti M35, 2006 - 2010 Infiniti M45, 2008 - 2012 Infiniti EX35, 2009 - 2013 Infiniti G37, 2009 - 2017 Nissan 370Z, 2009 - 2017 Nissan Maxima, 2011 - 2012 Infiniti G25, 2013 - 2013 Infiniti EX37, 2014 - 2017 Infiniti QX50, 2015 - 2015 Infiniti Q40