Superchips 2855 Flashpaq for GM Duramax 3500 Truck LB7, LLY, LBZ and LMM Diesel 6.6L Complete drivetrain tuning for your 2001 - 2010 GM Duramax Performance, heavy load towing andfuel economy tunes included Speedometer calibration for axle gearand tire size changes from 26 inch - 38 inch Industry leading horsepower and torque gains Read and clear diagnostic trouble codes