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. The Hopkins Tow Doctor vehicle wire harness test performs a test on all tow vehicle functions. Includes 7 blades, 6 round, and 4 flat test connectors. The Hopkins Tow Doctor is designed so that one person can make sure their vehicle side wiring has been installed correctly.