Trüpower Motorsports Polaris RANGER 900, RZR XP 900 Side by Side Premium Direct Replacement Ball Joints are manufactured to meet or exceed OE specifications following rigorous quality control and product stress testing. Trüpower ball joints stabilize the suspension system so your side by side continues to perform the way it was meant to perform. Plain and simple, our Polaris RANGER 900, RZR XP 900 Side by Side ball joints are built to last so you can work hard and play even harder.