That is a junk piece. It's a resistor that you are to wire into your Intake Air Temperature (IAT) sensor wire. It is supposed to increase performance and HP by tricking the computer into thinking the intake air is colder, and denser, so it will increase the fuel mixture. This "device" has been advertised all over vehicle internet sites including this one. With headlines such as " 15 More HP for your Ford, only $69.00"
It's junk and could possibly cause problems. I would throw it away.