New headlight relay harness upgrade for Datsun 240Z, 1970-73. This wiring upgrade will allow a full 12 volts off of the battery to reach your headlights while still maintianing all of your factory switches. Results in brighter headlights with no dimming when other accessories are turned on. Simply plugs into the 240Z factory wiring harness with no cutting or splicing involved. Great upgrade for stock headlights or newer H4 style bulbs.