Air Lift Ultimate kit 88295 has an internal bumper inside of the air spring which the standard Air Lift 5000 kit does not. The internal bumper prevents the air spring from bottoming out which can damage the air spring. The most common cause of air spring failure in the standard 5000 air spring kit is running them without the minimum air pressure. The 5000 Ultimate allows you to run the air spring without air pressure and eliminates the bottoming out concern. The internal jounce bumper in the spring also provides extra support.