Review on MaxxHaul 70086 7-Way Round to 4-Way Flat Trailer Plug Adaptor: Flexible Cable, Extendable up to 36 Inches, Red by Bim Cook

Heavy Duty Adapter. The plugs are made of thick plastic, very good weatherproof. Wire has heavy gauge insulation over 18 AWG. I bought it to use between the truck and our grain trucks. The spiral cord keeps the wire up and out of the corn stalks. If it can withstand the rigors of agricultural use, it will certainly handle regular road traffic as well. You can't beat the price. A regular 7 to 4 pin adapter costs the same or more.