There's no need to buy multiple trailer connectors when you have the ALEKO trailer adapter. Our 7-Way Round Terminal to 4-Way Adapter converts 7-way vehicle connectors with round terminals to a standard 4-way connector. An adapter is an electrical device that allows a connection to be made between a mismatched trailer plug and vehicle socket. Easily plugs in your vehicle's electrical socket , usually requires no additional wiring. Durable, tough plastic cover adapter.