Design Engineering 010504 XL Protect-A-Boots Spark Plug Boot Protector Sleeves, 8" - Silver (Pack of 8) Helps prevent burn-through, hardening, and cracking of boots from under-hood heat Withstands 1200F direct continuous heat Non-flammable, protects against chemicals, and resists water Double-wall construction for added durability Universal-fits most straight or angled boots; installs in seconds