2006-2010 GM Duramax 6.6L, LLY/LBZ/LMM. Corrects speedometer & odometer readings for non-stock tire sizes & gear ratios. Reads and clears diagnostic trouble codes. Internet upgradeable to a Max Energy Power Programmer! With Max Energy upgrade you can add HP & Torque, change top speed limiter, rev limiter, transmission shift points and more!