ACDelco Silicone Dielectric Grease is designed primarily for automotive spark plug boots and electrical connectors. The grease may also be used as a seal and lubricant for cable connectors, battery terminals, rubber door seals, and plastic O-rings. ACDelco Silicone Dielectric Grease is a polytetrafluorethylene (PTFE) thickening silicone grease that has a broad temperature range (-40 degrees Fahrenheit to 392 degrees Fahrenheit/-40 degrees Celsius to 200 degrees Celsius), excellent dielectric strength, is oxidation resistance, water repellent, non-corrosive, chemically inert (except towards silicone rubber), and has a long shelf life. Do not apply to silicone rubber components, as the grease will react with and harm that material.