A sway control unit is an inexpensive solution to the problem of a wandering trailer. CURT sway control units are designed to attach to your vehicle and trailer at the coupling point and counteract any lateral movement in your trailer, keeping your tow load straighter on the road and giving you more control over your vehicle. The sway bar uses material like that used in brake pads to provide the necessary resistance while still allowing your vehicle to complete proper turns with your trailer attached. The sway control mounts onto the frame of your trailer and connects to the vehicle's ball mount using a separate trailer ball from that used for coupling the trailer. This sway control replacement ball is designed to attach a sway control unit to the vehicle-side of the connection. With its 5/8" shank diameter, it mounts into the mounting tab of a weight-distribution hitch or a sway control ball mount. It features a ball diameter of 1-1/4" to fit the CURT sway control unit #17200 and features a chrome-plated finish for long-lasting rust resistance.