Evenly distributes weight over axles of the tow vehicle and trailer Steel-on-steel friction minimizes sway Round spring bars flex for a controlled ride L-Brackets keep spring bars in place Clamp-on brackets Pre-installed 2-5/16" hitch ball Powder-coated steel construction. This weight distribution kit is designed for trailers that have tongue weights that range from 800 lbs to 1200 lbs and/or no more than 12,000 lbs of gross trailer weight.