DEI has taken premier Titanium LR technology and transformed it into the best protection sleeves on the market. DEI Titanium Protect-A- Sleeves are capable of withstanding temperatures up to 1,800 degrees F direct heat and 2,500 degrees F radiant, shielding your wires, lines, and cables from damage. The sleeves are available in 4 ft. lengths. The 1/2 in. inside diameter will fit larger spark plug wires to protect them from hot exhaust manifolds and headers.