This custom BOSS secondary clutch is an excellent upgrade for 2015 (Not 2016) RZR 900's & 2014-Up Ranger 900 models. We cut our own angle into this clutch and use a custom spring to achieve maximum performance. The stock secondary is very lazy and does not transfer the power to the wheels as quickly as this clutch will. The shift is slow, where as we speed up the shift allowing for more wheel speed and much faster acceleration. Back shift is still very fast for excellent corner to corner results. This secondary clutch MUST be used with our stage 1 clutch kit. When you receive our setup sheet, you will use the stage 2 weight setup chart.