This is a Hewitt Gen 2 secondary air injection system bypass kit to fix the notorious secondary air system caused fault codes, which can put the vehicle into limp mode. It has not been used, it's still in the box it came in with all of the instructions. One bag was opened to inspect it when I got it. I bought this for a 2005 Tundra and the truck got in a wreck before I got around to installing it. It works on multiple vehicles using the 4.7 L V8 engine, you can check on the Hewitt website if you are uncertain. This retails new for $450 from Hewitt, so this is a great deal if you need this. I will only ship within the United States. Shipping is free!