This is a Stainless Steel Wear Sleeve, the same one that comes standard on all Dexter Axles with a #84 Spindle. Axles that would require this Wear Sleeve are typically in the 5 Lug category. An axle's Wear Sleeve should not rust, since it's made of Stainless Steel, but it may become damaged or dinged from road debris or accidents around the hub or grease seal area. Once the Wear Sleeve is no longer providing a smooth surface for the Grease Seal, it's time to replace it. Any type of dent or ding in the Wear sleeve could cause Grease to leak out the back or could tear the grease seal while trailering and cause a seal failure.Features:-Fits #84 Spindle-Stainless Steel-Provides smooth surface for the Grease Seal