Ultra 47(TM) Sheath line sleeve has a higher sustained heat capacity of up to 1100F and is more flexible and light weight that standard foil or bonded aluminum products. Ultra 47(TM) thermal heat sheath is constructed from a process that impregnates molten aluminum to the core fabric giving it higher heat reflective properties. The perfect choice for tight high heat applications. Easy to cut & trim to length Ultra Lightweight: 40% lighter than most line sleeving DO NOT apply directly to exhaust components.