Pedders Air Assist Bellows system improves the towing ability of the vehicle, as well as compensating for minor sagging in the rear associated with carrying weight. The Air Assist Bellows system also restricts 'bottoming out' caused by the load or travelling over rough and uneven terrain. It is recommended, that replacement leaf springs be installed if they show signs of fatigue, in that they have sagged significantly.
Note that Pedders Air Assist products DO NOT increase the vehicles Gross Vehicle Weight.
Features & Benefits

Exceptional Load Carrying
Ability to deal with large load changes
Load Assistance
Restricts bottoming out under load
Maintain Comfortable Ride