It's a good idea to relay your fuel pump for the street and a must when you're racing. Designed specifically to prevent voltage drops at the fuel pump to maintain constant fuel pump pressure and to prevent fuel pump amperage overloads from damaging the vehicle's electrical system. Kit includes: 30-amp heavy-duty relay, relay base with wire harness (6' input, 6' output), 30-amp circuit breaker, crimp-on terminals and mounting hardware.