Sonoreboom Heat Sleeve Automotive:High temperature heat shield sleeve is made of interwoven fiberglass;designed for car & auto etc brake line hose heat sleeve cable;help to cable,wire prevent vapor lock,protect spark plug wires from melting and protect sensitive wire looms from proximity heat,shielding brake lines and hose and stopping clutch cables from melting Fireproof and Radiation Resistance:Sonoreboom spark plug protector sleeve operating temperature:- 418 - 1382 ;withstands operating reflective temperature of 600 continuous and 1500 intermittent; Simply pull the wires inside,AN hoses,cables etc;capable of reducing up to 60 - 80 percent per radiant heat