As the name implies, the frame is on the perimeter of the load. This beam arrangement uses bolted, cross members that are installed at specific places along the length of the beam to support the loading. Most frame sections are extendible on the width. This means that the frame can be widened to house the load between its frame rails and to reduce the overall width when empty. This configuration typically needs toque tubes at the front and rear to widen the frame from the gooseneck and tail section.