... )connect H4 hid lamp with ballast 2) UL certificate HID Relay Harnssuse for H1,H1 Metel, H3, H4-1L,H4-2H ... -Xenon,D3,D4,H6 and so on.H4 halogen/xenon relay harness to get enough power for some cars to install ... hid kit on.Details: Auto Relay harness are used as the auto HID kits wire harness ... car types, like some USA car and Asia car. HID Relay Harness