Not all trailer couplers and vehicle hitches are the same height. Due to this, some vehicles will require extra length on the trailer wiring to plug in to the tow vehicle and provide enough slack for turning radius. The 47015 Flex-Coil adapter provides this extra reach while ensuring that the wire will not drag due to the Flex-Coil design. Nite-Glow connectors illuminate upon activation of the taillight function to verify electrical continuity between the vehicle and the trailer.