This package includes Eibach Pro kit springs and professional installation. These springs offer a progressive rate and roughly a 1" drop front and rear. The drop gets rid of the excessive wheel gap that comes along with the factory ride but isn't too low that you'll be rubbing everything. These springs ride good enough that any ill effects are barely noticible and handling will improve. We have installed many of these kits with no complaints so far.
Note: a full 4 wheel alignment by a professional alignment specialist is highly recommended following installation.