This spring kit gives a substantial improvement in ride quality while improving handling as well at G-out resistance. We've found the perfect combination of spring length to rate ratio and are very happy with our results. This kit is for all four corners of the machine. After a lot of testing, it was determined there is no need for a dual-rate spring setup on the front of a Standard RZR. We decided to stay with the proven single rate spring setup we've been using for years on the front. The rear however has found large improvements by switching to a dual-rate combination. We provide a short spring, a long spring and a delrin spacer for each shock. The delrin spacer has two different guide shoulder lengths designed into it to provide adjustability for the user to modify when the secondary spring kicks out and the system goes to a linear rate. The secret is in our short springs. We've found a perfect universal rate which allows us to custom tailor our long springs, (which determines the final rate of the suspension) to each individuals needs. We have narrowed it down to two options; Medium and Heavy. The medium set is a perfect improvement over stock for recreational drivers without very much extra weigh added to the vehicle. The heavy rate is perfect for the aggresive driver, intermediate racer or for a vehicle with some extra weight in accessories or passengers. Of course because we can make all the adjustments with one spring per shock we are able to sell individual long springs to people looking to "tune" there springs sets in to there specific liking. We will list the two standard packages which will cover about 90% of all users. If you would like to discuss a custom combination feel free to call and an engineer can help you find what you need.