im no expert but basically it hooks to the middle of the car stopping upward movement lower than the cylinders can push it...you dump one side and pump the other....when the chain stops and the cylinders keep extending it pivots and pushes the extending side of the car up...
http://www.layitlow.com/tech/suspension_ch...ainbridge.shtml
http://www.layitlow.com/tech/suspension_ch...ainbridge.shtml