Relay works with your tow bar wiring system to ensure that your towed vehicle's turn signal lights flash in tandem with your RV's lights. Keeps your towed car's brake signal from overriding the turn signal sent by your RV. Allows signal lights on towed car to flash in tandem with RV lights even when vehicle's brake pedal is depressed. Required on towed cars with combined lighting if you are using a supplemental braking system. Needed on applications with separate lighting if towed car is wired using a TrailerMate wiring harness or a 4-diode kit (instead of a 6-diode kit). Does not interfere with towed car's electrical system.Activates automatically when RV running lights are turned on.Includes all necessary components for standard installation.May require additional connectors and length of wire for certain applications.

 PROP 65 WARNING: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling. For more information, visit www.P65Warnings.ca.gov