Aluminized material reflects away radiant heat, shielding plug boots from burn out. Protect your expensive plug wire sets and increase their life and performance. Reflect-A-BootsT prevent misfires caused by plug wire burn out, which may cause critical engine damage. This will save you time, money, and a problem in the future. Boots withstand 1100°F continuous of radiant heat and up to 500°F of direct contact. Installation is a cinch and these boots have a universal design which allows them to fit most boots-even 90°.