United Performance Products PROSTREET Aluminum Heat Shields Are Designed For Both Street And Race Applications and are Perfect as an OE Direct Fit Replacement. Our Shields Will Slide Over The OE Spark Plug Boot and are Installed with No Tools Required. Spark Plug Wires and Boots will Last Much Longer with the Additional Heat Protection Provided by the Aluminum Heat Sleeves. A Spark Plug Heat Shield reflects radiant heat, preventing lasting damage to the wire.