Hopkins Nite-Glow 4 Flat to 7 Blade Trailer Adapter 1.88 in.

This adapter converts a 7 blade vehicle connector to a 4 flat trailer side connector. Its Nite-Glow function checks to see if you are getting power from the tow vehicle and confirms you have installed the adapter properly. If the connector glows red, you have a solid connection. Also, includes dust cover for 4 Flat to help prevent corrosion.