The standard clutch version (non ebs) of the 900 RZR / RZR S is quite well calibrated from the factory for stock tires and trails.Testing of the vehicle showed that for most typical trail / mixed use of the vehicle with stock (and most 26- 27") tires, the stock clutch calibration was fine and no clutch kit is necessary. For many, that means, save your money. This kit is for re-calibration foruse in sand dunes, or with oversized tires 28+.
This kit can also be used to help with power losses from higher elevations that are typically above 4000 ft.
This is an adjustable kit that can be set up for different tires and situations. For 27" heavy mud type ( that measure a full 27" tall and are heavy versions) and all 28"+ sizes, this kit is used. The instruction manual has a "set up guide" that shows how to set up the kit for your application.