Bought a set of 4 Hellas (rectangular), and the low beams came with the reversed wiring plug adapters. Use the original wiring to fire the relays, and wire the relays to the battery (or alternator stud) with a circuit breaker. On my '84 gmc, it picked up 1.6 volts, my '79 Dodge van only gained 1.1 volts. Made a big difference.