OEM Standard: When you need to ensure a perfect electrical connection, you want dielectric grease! Why else would so many vehicles roll off the production line with dielectric grease in between the headlight harness and the back of the original halogen light bulb?
Non-Corrosive: Dielectric grease is the best and cheapest insurance policy you can buy to ensure that your new high-performance headlight system works forever. By protecting the contacts from moisture, you protect them from corrosion, and that's important for so many obvious reasons.
Non-Conductive: In addition to the rubber seals built into most connectors, dielectric grease adds a second layer of protection by acting as a moisture-barrier. If you use your vehicle year-round, rain or shine, then this is a no-brainer for your build.
Lasting: Each tube is more than enough to coat the connections on a full HID upgrade using a traditional relayed wire harness. A little bit of this stuff goes a long way!