A weight-distributing hitch is a "load leveling" hitch. It is a hitch setup mounted on the tow vehicle that uses spring bars and chains under tension to distribute part of the trailer's hitch weight from the towing vehicle's rear axle to the towing vehicle's front axle and to the trailer's axle(s). It can help reduce trailer sway and hop. Trailer hop can jerk the tow vehicle. Trailer sway is also called fishtailing. At high speeds, trailer sway can become dangerous. Most vehicle manufacturers will only allow a maximum trailer capacity of and of tongue weight without using a weight-distributing hitch. Tow vehicles often have square receiver sockets to accept weight distributing hitches.
