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 1991 - 1997 Toyota Previa, 1986 - 1992 Toyota Supra Fitment: 1986 Toyota Supra Base 1987 Toyota Supra Base 1987 Toyota Supra Turbo 1988 Toyota Supra Base 1988 Toyota Supra Turbo 1989 Toyota Supra Base 1989 Toyota Supra Turbo 1990 Toyota Supra Base 1990 Toyota Supra Turbo 1991 Toyota Previa DX 1991 Toyota Previa LE 1991 Toyota Supra Base 1991 Toyota Supra Turbo 1992 Toyota Previa DX 1992 Toyota Previa LE 1992 Toyota Supra Base 1992 Toyota Supra Turbo 1993 Toyota Previa DX 1993 Toyota Previa LE 1994 Toyota Previa DX 1994 Toyota Previa LE 1995 Toyota Previa DX 1995 Toyota Previa LE 1996 Toyota Previa DX 1996 Toyota Previa LE 1997 Toyota Previa DX 1997 Toyota Previa LE