1. This is one complete 36-inch extended-length RS 9000X as shipped. The two Eibach springs are included in the price, and you can pick your rates anywhere in a range between 80 and 350 lb/in. The shorter 12-incher goes on the top and is a lighter rate than the longer 14-inch unit which is installed on the bottom. The formulas to figure out the proper spring rates for your rig can be found on Rancho's Web site. Be prepared to know the weights of various components of your rig in order to dial in the proper suspension tuning for it.