"Four" American Star 4130 Chromoly Racing Ball Joints For Listed Models Of Polaris RZRsM odels The Very Strongest Polaris UTV Ball Joint Made. Period! Is your Polaris RZR, feeling a little lose in the front end. If so, here is the answer to your problem at less than half the price of Polaris OEM Parts. This ball joint is manufactured out of 4130 Aircraft Grade Heat Treated Chromoly and has a tensile strength of over 4 times the original OEM Factory part number. It is designed for racing and heavy duty applications as well as for OEM relpacement use. Plus they have a 90 Day Replacement Warranty! Included in the American Star Ball Joint Replacement Kit Is: 4 American Star Heavy Duty 4130 Chromoly Ball Joints with Clips. The cost of these parts 4 from Polaris with a discount is $180.36 for 4 Ball Joints and retaining Rings or $45.09 Each!!! The American Star kit is 4 times stronger, excellent quality and is less than half the price! You ask why so much less money for ours? We are the manufacturer and not a dealer. Buy ours and use the money you save to buy more cool stuff for your RZR! Have a great day and thanks for looking! Fits the following: RZR 900 50/55 Inch 15-up RZR 4 900 15-up RZR 900 60" 15 up RZR 900 60" PS 15-up