LIFETIME ACCESS - GIVES YOU ACCESS TO THE COMPLETE AMDP CUSTOM TUNING LIBRARY FOR THE LIFETIME OF THE TRUCK OR UNTIL AMDP DISCONTINUES SUPPORT. Power Levels: Level 1: 30HP (Stock/Optimized & Heavy Tow): Ideal for users only wanting to add a bump in power and enhanced drivability or heavy towing applications over 12,000lbs Level 2: 70HP (Light-Moderate Tow): Ideal for users who tow up to 12,000lbs Level 3: 100HP (Performance): Ideal for users who want significant horsepower & torque gains Level 4: 150HP (Performance): Ideal for users who want significant horsepower & torque gains Level 5: 200HP (Race): Ideal for users who want to maximize power on their off-road or race applications Race Pipe Fitment & Features 2011-2016 Chevy/GM 6.6L Duramax (PLEASE SELECT CORRECT DOWNPIPE STYLE) NOT Compatible with Cab & Chassis Trucks DESIGNED TO FIT ALL CAB & BOX CONFIGURATIONS, MAY REQUIRE SOME MODIFICATIONS T409 Stainless Steel Easy Installation w/ Pre-bent Exhaust Hangers Stainless Lap Joint Clamps ALL TUNING IS VIN LOCKED AND NON-REFUNDABLE.