This kit allows the conversion from factory springs to aftermarket 2.5" springs. This kit is only available for Koni's at this time. The benefits of going to the 2.5" springs are:
Easier installation/removal through the upper control arm
More room for wider tire/wheel combinations
Infinite spring rate choices
Ability to change springs without a spring compressor
In addition to this kit you will need threaded collars, thread tubes, and springs, as well as Koni shocks.
Pic of assembled shocks is only for reference on what the completed package could look like.
Instructions available for the conversion are included.