The Back-Up Warning Wire is a ground wire. It is used to connect the backup warning unit to the vehicle's electrical unit and provide a path for current to flow. The black wire is connected to the negative terminal of the battery or a metal body bolt. Attributes:● Provided with a Connector for secure connection and power supply● Manufactured to precise specifications and is durable and reliableApplications:The Back Up Warning Wire is used for supplying power to the back up warning unit.