This kit is a plug-and-Play harness using sealed relays and OEM connections designed to drive AND brighten the headlight system for late model Corvette using the H4 EURO spec. headlamp housings. System attaches to the alternator stud or battery positive junction and increases brightness by as much as 30%! Necessary addition when using high wattage H4 bulbs. Sealed relays included. Top quality kit uses all OEM wiring and connections.