Reese Towpower Professional Series combination connector offers the most convenient way to wire your vehicle to accommodate both a 7-Way connector and a 5-Flat connector. The 5-Flat connector is designed to handle the needs of most boat trailers where the surge brake systems need to be deactivated when backing up the trailer. Most 4-Flat connectors can also be plug into the 5-Flat connector giving greater flexibility to tow different trailers. The heavy duty stainless steel spring on the gasket sealed 7-Way connector cap, assists in keeping moisture and dust out of the electrical connections when not in use. Removing the snap on wire protector allows full access to the tin plate terminals for easy wiring. Look for other durable Professional Series Reese Towpower products to meet you electrical towing requirements.