Permatex - Dielectric Tune-Up Grease - 3 oz. - 22058. Permatex Dielectric Tune Up Grease protects electrical connections and wiring from salt, dirt and corrosion. Dielectric Tune Up extends the life of bulb sockets and prevents voltage leakage around any electrical connection. Also prevents spark plugs from fusing to boots. Use Dielectric Tune Up for modern high energy ignition systems.. Features:. Size - 3 oz.. Protects electrical connections and wiring from salt, dirt and corrosion. Prevents voltage leaks around any electrical connection. Extends the life of bulb sockets. Required for modern, high energy ignition systems. Prevents spark plugs from fusing to boots