The box is the flashing device. You have to purchase bullet or credits. And then you. Read the file with the box. Load it in your pc. Get the template code. And then tune off that. you have to run a few programs. 1 allows you to add credits, another reads and writes to the flash box. And the other is your tuning program. One big downfall. if you tune a vehicle. Then later the customer comes back. You have to have the file on your pc. You cant read the file unless you buy another crrdit.