Aluminized material reflects away radient heat, shielding plug boots from burn out. Protect your expensive plug wire sets and increase their life performance. Reflect-a-boots prevent misfires caused by plug wire burn out, which may cause critical engine damage. This will save you time, money, and problems in the future. Boots withstand 593.3°C (1100°F) continuous of radiant heat and up to 260°C (500°F) of direct contact. Installation is a clinchand these boots have a universal design which allows them to fit most boots, even 90°