1、Trailer Plug Wiring Harness: Made of solid copper wire and PVC, this trailer plug wiring harness is weatherproof and can withstand various harsh conditions to ensure a longer lifespan. 2、Truck Extension Adapter: Designed as an extension adapter for truck existing towing wiring, it plugs into a 7 way RV blade socket for connecting 5th wheel wiring or gooseneck wiring. 3、Stable Signal Transmission: With a 7 core design, which ensures accurate and efficient signal transmission for a more reliable electrical connection between towing vehicle and towed vehicle. 4、Universal Application: Suitable for all types of vehicles including trailers, RVs, cars, and boats. Perfect for connecting tail lights, brake lights, reverse lights, turn signal lights, and auxiliary power. 5、Weatherproof and Long Lasting: Constructed with premium materials, this 3FT 7 way trailer plug wiring harness is resistant to wind, rain, high low temperatures, wear, and oil.