Dielectric grease omits oxygen, water and salt, and is an excellent insulator. Perfect for trailer hitch connectors, switch panel contact lugs, in-line fuses, fuse panel fuses and screws and light bulb contacts. The grease DOES NOT REMOVE CORROSION, however, so use on all new and clean installations and any place where contacts are already good. On trailer hitch wiring reapply at least twice each year. IF you use this on everything I suggest looking for a larger tube on the web--at least 6-8 ounces. This product is only a fraction of an ounce.