Unparalleled mechanical friction Sway Control that self-adjusts So quiet you won?t even know it?s there ? no rattles, clicks, squeaks or groans! Patented True Motion-Dampening system ? drastically reduces bounce Greaseless system ? ball and coupler move as one Easy install ? no pry bars needed! 50mm, 350kg ball included and no extras to buy One-Pin removal from tow vehicle Doubles as a standard ball mount for towing without weight distribution 4?or 8? drop/rise adjustable shank The smoothest ride around ? owners are saying they can?t believe it! No problem backing up ? even reversing your trailer is easy. No binding or locking up Weighs under 27kgs 3500kg ATM 350kg Tongue/Ball Weight Limited Lifetime Warranty