Protect your expensive plug wire sets while increasing their lifetime. Insul-Boots prevent misfires caused by plug-wire burnout. This helps prevent loss in performance and critical engine damage. Double wall construction provides superior protection. Special coatings allow boots to reflect and dissipate heat. Insul-Boots are available in six colors-red, blue, black, beige, yellow and orange. They withstand up to 1200°F. Universal design fits most boots-even 90°. Easy installation: place ring side on end of spark plug boot and slide the open end towards the wire. Size: 1" id. X 6".