Heatshield Products Lava Boot Shields™ feature a no-fray cuff with a flexible dual-wall high-temperature basalt sleeving with a 1,200-degree F working temperature that prevents plug and wire burnout even in the most demanding ambient heat applications. Lava Boot Shields™ help eliminate misfires caused by plug-wire and spark plug boot burnout, helping prevent critical engine damage and loss in performance from a cylinder not firing. In addition, Lava Boot Shields™ protect your wires and boots from being damaged by excessive engine and exhaust heat. The universal design fits most boot sizes and angles, including 90-degree boots. We have standard sizes, which are a great fit for most engine applications, and our 8-inch-long 1-1/4-inch internal diameter Lava Boot Shields are great for LS engines.