Fifth wheel

A fifth wheel is a type of hitch used to connect a large trailer to a truck or semi-truck for towing. It consists of a coupling device mounted in the bed of the truck, which fits into a matching trailer's kingpin. This setup provides a strong, stable connection that allows the truck to safely pull heavy loads, especially in the transportation of goods. The term "fifth wheel" comes from the shape of the coupling, which resembles a wheel. It’s commonly used in commercial trucking, facilitating smooth turns and better weight distribution for oversized cargo.