RFI Shield reduces Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI) from ignition systems & high voltage wires that can affect computer systems, electronic fuel injection, radios, and other sensitive components. Electronic fuel injection systems thrive in an environment free from RFI. RFI Shield safeguards the delicate electronic components, optimizing fuel delivery and engine performance. Drive with confidence, knowing that your vehicle's critical systems are shielded from interference that can compromise safety and performance.