This kit includes two rear spring adjusters/preload assemblies that not only level the rear suspension, but will lower or raise the fixed assemblies that were stock.  It also prevents spring float in negative G situations.  Assembly instructions are included where drilling and cutting is required.  Also included are two female heims in the event your suspension needs to be raised more and additional spring attach bolts of different lengths to cover varying spring thickness.
Other kits similar that are inferior sell for near double our price!