The Reese Towpower 7-Way to 4 or 5-Way Adapter with Built-in 12V Power Outlet easily adapts OEM 7-way blade connector to either 4-flat or a 5-flat connector. Instantly checks basic trailer electrical circuits for connectivity and displays the connectivity using high visibility LED's. The attached dust cover keeps terminals clean when not towing a trailer and an extra attached terminal plug to cover 5th post of 5-flat when only using the 4-flat connector. REESE is the market leader in automotive and recreational product solutions, engineered and designed to meet the demands for work and active lifestyles. REESE Towpower pioneered the technology that has set the standard for today's most advanced towing systems. We cater to the towing needs of everyone from recreation enthusiasts to heavy-duty agriculture users by manufacturing the largest selection of receiver hitches; ball mounts and hitch balls; trailer and hitch locks; couplers, jacks and winches; and electrical and lighting components that meet and exceed industry standards.