For 2005-newer vehicles. The MAC10 is a tool that allows you to read and write to your vehicle's pcm. Once a file is read from the vehicle, it can be emailed to us or one of our dealers to modify or create any custom tune that you may need. The tool is easy to use and transfering the file from the tool to your pc is a breeze with the removable SD card. The MAC-10 comes supplied with one Bullet (password to tune one vehicle*) and additional Bullets can be purchased to tune additional vehicles without having to purchase another tool.* The 6.4L Ford diesel requires 2 Bullets to tune.