25 ft. of Black Silicone with numbered shrink tube ends to label plug wires to the correct cylinder. Annealed Fiberglass sleeve is coated with Silicone providing excellent resistance to abrasion fraying and punctures. Resistant to chemicals and extremely flexible heat resistant to 500 F makes it the perfect choice to cover and protect your spark plug wires. High dielectric strength for high voltage coils and ignition systems. Kit includes: 25 ft. - 3/8 in. ID Silicone covered Annealed Fiberglass Sleeve 8 - DEI branded high heat shrink tube ends 8 - Numbered 1-8 high temp shrink tube ends