The 61000 Performance Module fits 6.6L GM Duramax trucks (LB7 engines) from 2001 thru 2004. This diesel performance module is designed for fuel economy with up to 30% increase in hp and fuel savings up to 10%-20%. Adjustable with a four-position switch you can adjust the power on the fly, Stock, +30 HP 60 HP, & +90 HP. The module doesn’t flash the ECM, instead it receives the data from the ECM, optimizes the signal to the engine improving the fuel efficiency and power. These savings ensure a quick return on investment so you can enjoy greater efficiency and less cost. Plug-and-play connectivity means there’s no need to cut, splice or modify engine wiring. All Ag Diesel Solutions modules are Made in the U.S.A.