The torsion component in Rota Flex's head absorbs the motion. The jounce stops also absorb motion as well as eliminating any over travel condition. The major benefit is the dramatic reduction of fore to aft movement, a.k.a. "chucking", typically felt inside the tow vehicle. In addition vertical force is absorbed in the torsion section of the pivoting head that would otherwise transfer into the trailer frame with a standard pin box. Rota-Flex provides a life enhancement for the occupants of the tow vehicle and improved durability for the trailer. Rota-Flex is easy to install as a bolt on application into the pin box sleeves of the major pin box models found in the RV market. There is no assembly required. Rota-Flex has been thoroughly stress tested and is CSA (Canadian Standards Authority) approved in its application.