This ring and pinion gear set is computer designed, precision CNC machined and heat-treated to ensure the highest quality possible. One of the quietest aftermarket gear sets on the market. Available in any gear ratio for street or race - please specify gear ratio (3:00, 3:25, 3:50, 3:70, 3:89, 4:11, or 4:30) and application when ordering. Optional REM treatment and/or lightening available.