This Kit Includes Premium Wheel Bearings with Tough Steel Seals and 100% 304 Stainless Steel Axle(s). If Your Machine Needs Wheel Bearings, it is Very Important to Check Your Axles for Wear or Rust. Factory Axles are Much Softer Than the Bearings and It is Highly Likely That The Old Bearing Has Damaged the Axle. A Damaged, Rusted or Worn Axle Will Significantly Shorten the Life of The Replacement Bearing. HD Switch Axles are Made of Hard Seamless 304 Stainless Steel (304SS) and Will NEVER Rust. 304SS is Harder, Tougher and Will Last Much Longer Than a Soft Carbon Steel Factory Axle. Our Bearings are World Class Quality and Use Tough Steel Seals.