Hypertech 32003 Max Energy Power Programmer for 2006-2009 GM Duramax 6.6L LLY / HO LBZ / LMM 3-Stage power tuning; tow safe in all power levels up to maximum GCWR Adjustable top speed limiter (not available on all vehicles) Speedometer/odometer recalibration for non-stock tires and rear end gears (not available on all vehicles) Reads and clears Diagnostic Trouble Codes (DTC's) Features easy plug and play design