This is a used tuner I had on my 2002 Chevrolet Duramax Diesel. The tuner will work for 2001-2005 Chevy Diesel trucks. I only used the tuner for a few months before getting a new truck. It worked well while I used it. There are four tunes pre installed in it  and I think you can customize your own tune. I have all the hardware and the software is uninstalled so it is ready for a new truck. I also have the usb with the software and the installation instructions that I will be sending the new owner. 

Let me know if you have any questions. 

Buyer pays $20 to ship USPS.