Hitches bolt to chassis of vehicles to connect trailers and other extensions for towing purposes. Towing hitches are sold by classes from 1 to 5, with Class 1 being for light-duty towing and Class 5 being the heaviest-duty towing option. Hitches may be front-mounted, rear-mounted, attached to bumpers or bolted to truck beds. Hitches use accessories like spring bars, chains, and slings to help hold vehicles in place during towing. Hitches and accessories use tension to distribute part of the trailer's weight from the main vehicle's rear axle to the towed vehicle's front axle.