Universal Standard - The 7 pin extension cable cooperates freely with a 7 pin socket and plugs into the European standard to power a trailer or caravan. Easy to install - 12V 7 pin towing electrical assembly with 2M coiled cable, ideal for extending the connector between the trailer and another car. Durable Quality - This 7 way trailer plug and socket are made of high quality plastic and brass pins.And they are certified by RoHS. Waterproof Design --- Plastic housing prevents rust or corrosion, allowing for a long service life. Safety Assured - The 7-pin round trailer adapter plug establishes a secure connection between your primary vehicle and the additional trailer to transfer electronic signaling signals and power.