This electrical converter is used to exchange a 4-pin vehicle plug for a 7-pin European plug. A dust cover is included on the side of the 7 pin Euro trailer to keep the plug clean when not in use. The plug-and-play design minimizes the need for new cables inside without the need for additional adapters. Wiring of 4 way American flat connectors on trailers with European 7 way trailer wiring. Converter with the function of separating the "stop" signal from American vehicles with a 2-wire system Installation guide: Before connecting the inverter to the vehicle, check that All vehicle signals are turned off. Connect one side of the converter to the existing 4 way US flat connector vehicle. Insert the other EU trailer plug into the plug converter. Check that all connections are secure. No maintenance of the power adapter is required during use. Colour:Black Material:plastic Package Contents: 1x Trailer light converter 1x ball Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.