Hopkins Manufacturing Corporation makes your towing experience simpler and more rewarding through innovation and value. Hopkins offers a variety of towing solutions including vehicle wiring kits, adapters, vehicle and trailer connectors, breakaway systems and much more. Today, more than 40 percentage of retail category sales are generated from Hopkins innovations. Five pole rounds provide one additional function not found in 4-poles. This extra function is typically used for electric brakes, auxiliary or backup function.