The BulletProof Sway Control System helps to eliminate the sway that can happen while towing; this could be from wind, passing vehicles or uneven road surfaces. The system connects from the front of the trailer to a mounting point on the hitch and is designed to stiffen the connection between the vehicle and the trailer, keeping it straight and in-line while towing. It is most useful when towing travel trailers or toy haulers and is designed for a safer towing experience. In order to use this system with any steel Medium, Heavy or Extreme Duty BulletProof Hitch®, it must be paired with either a BulletProof Medium Duty Sway Control Dual Ball or a BulletProof Heavy/Extreme Duty Sway Control Dual Ball (sold separately). It is also important to note that the BulletProof Sway Control System MUST be disengaged or removed before reversing. When it comes to removing or disengaging the system, this is a simple process or removing the two retaining clips. For trailers that are up to 10,000 pounds and up to 24' in length, one BulletProof Sway Control System is recommended. For trailers that are over 10,000 pounds and/or over 24' in length, two BulletProof Sway Control Systems may be required Note: The BulletProof Sway Control System is NOT compatible with trailers that are equipped with surge brakes.