Reese Friction Sway Control. It operates on the principle of "stiffening" the coupling between the tow vehicle and trailer. The degree of "stiffening" or friction is adjusted to suit various trailer weights and towing conditions. Its operation is simple and uncomplicated. It doesn't prevent the generation of sway; it simply works to resist the forces once they have started. Features of Reese 83660 Friction Sway Control Installs and removes easily Heavy construction for added reliability Friction brake keeps trailer and tow vehicle stable Quick attachment to trailer frame and ball mount Can be used on left and right side of trailer Package Contents: Reese 83660 Friction Sway Control Reese 83660: Friction Sway Control