Since 1977, Direct Dimension Inc. has manufactured one of the most important, but seldom seen, components of the hundreds of thousands of tractor-trailers that crisscross America. The so-called "5th Wheel" is the coupling that connects the trailer to the tractor, and "The Revolver" is so safe, efficient and reliable that DDI guarantees it for 10 years or one million miles. A grease-less coupling system, The Revolver uses a top-of-the-line kingpin, a polyethylene rotating disc, and a corrosion-resistant retention ring to achieve 75 percent less friction when compared to a fully-greased 5th wheel. That's good for the environment, too, with no grease-disposal or grease-storage issues to deal with. The Revolver, built in Direct Dimension Inc.'s Crystal Lake plant, generates superior handling, increased productivity, lower operating costs and extended trailer life.