The Corvette Envy C5 Hi-4 Harness (C5 Headlight Relay Harness) will allow your low beams to remain on with your high beams which allows you to double your headlight lumens. The harness includes a main fuse which is in addition to your existing headlight fuses so that you get double protection with this harness. The Hi-4 harness installs in the under-hood fuse panel area in less than 5 minutes. All you need is a 10 mm and ½” socket wrench and a 3” extension. If you change your mind on this harness you can uninstall it and the Hi-4 harness leaves no permanent modifications on your C5 Corvette. This modification is designed specifically for rural highway driving or poorly-lit road use. Please keep other drivers in mind when using this light output modification. High beams are naturally aimed higher and will likely impair oncoming drivers.