Wesbar 7285 18" Trailer Connector. 4-Way Harnesses & Connectors. Wesbar harnesses conform to all applicable SAE, NMMA and TMA standards to provide years of dependable service. Standard 4-Way harnesses have an 18" ground wire except where noted. Wesbar's 5-way plugs mate with all Wesbar 4-way plugs and will operate all DOT required lights. Complete trailer harness kits listed include all trailer and tow vehicle harnesses, mounting hardware and instructions.