Description
Thick wall insulating hose, sold by the foot. It goes over a brake line or hydraulic hose to keep radiant heat off it, usually where a run has to pass a manifold, a header or a turbo and there is nowhere better to route it.
Thick wall is the whole difference between this and the heat protection sleeves in the same category. More material between the heat and the line, and more room taken up, so measure the gap you actually have before ordering rather than after.
Heat is what this is for. If the line is rubbing rather than cooking, the plain abrasion sleeve is the cheaper and slimmer answer.

