You need this if your HID lights aren’t working correctly- if one light only lights after both were working and you shut off and turn back on and one only lights and then you shut off and back on and light that wasn’t working is working - it’s the harness - normal life is 3-5 years for a harness - depending on conditions or use - the only problem I’ve had with this harness is it’s not wired correct at plug from factory at high beam wire - easy fix by switching wires on harness plug to match your factory wire plug.