Battery washers prevent corrosion and extend battery life, Battery Terminal Washers are designed to offer superior protection to battery post connections and ensure maximum life of your battery. These highly insulating synthetic felt washers help seal out corrosive vapor, moisture and dirt and are easily fit around all battery post sizes. Features - Prevents terminal corrosion - Long life synthetic felt washers - Insulates battery posts - Self adhesive backing for easy installation Benefits - Keeps your car's battery at full power for longer periods of time by preventing corrosion on the terminals and increasing the electrical connection stability - Properly insulated terminals reduce sparks on connections to eliminate potential hazards that could damage sensitive car components - Low profile design keeps terminals protected while providing a clean aesthetic under the hood.