Moose Racing Sealed Chain Roller The Moose Racing Sealed Chain Roller is made of polyurethane with a durometer hardness of 98A, so it lasts a long time. The sealed bearings keep water and dirt out. These rollers are made of Delrin and they lubricate themselves, which is a big upgrade from the original ones. Features: Polyurethane roller with 98A durometer hardness for long life Precision contact sealed bearings keep water and dirt away These rollers, made from Delrin, are self lubricating and offer significant improvement over the OEM Mounting hardware included Replacement OEM Numbers: 1590360, 3446381, 4391022A10, 4391035G00, 4391037F00