- High heat resistance: Each fiberglass sleeve withstands up to 1200 degrees Celsius, protecting spark plug boots and ignition components from heat damage generated by headers, distributors and turbo systems. - Wide compatibility and length: 6 inches long, designed to fit most straight or angled spark plug boots across a wide range of vehicles, including cars, trucks, SUVs and race cars. - Improved engine performance: Shields wires from heat exposure, helping prevent misfires and electrical shorts, resulting in a more stable engine operation and increased power. - Easy installation: Sleeves slide easily over spark plug boots without tools, enabling a quick and hassle-free ignition system upgrade. - Durable construction: Made from high grade fiberglass for reliable heat shielding in hot engine bays. - Applications: Use in performance street cars and race cars with headers or turbo systems to minimize heat soak; use in trucks and SUVs with demanding engine bays to prevent heat-related boot wear; ideal for drag or track vehicles needing consistent ignition under high heat.