Hypertech 32004 Max Energy Power Programmer for 2007-2009 GM Gas Truck/SUV - 4.8/5.3/6.0L Power tuning for regular, premium and E-85/Flex fuel vehicles Adjustable top speed limiter and engine rev limiter (not available on all vehicles) Speedometer/odometer recalibration for non-stock tires and rear end gears (not available on all vehicles) Automatic transmission shift point and shift firmness adjustments (most applications) Specific features like Power Tuning, Top-Speed Limiter, Speedometer Calibrator, Cooling Fan "On/Off" Temperatures, Return to stock or change option settings, Automatic Transmission Adjustments and few more for your make, model and year