WHEEL BEARING PROTECTORS Provides permanent protection against damage from water and dirt entering the wheel bearings. Prevent corrosion resulting from water entering the hub when the trailer wheels are suddenly submerged. Automatically maintain the correct internal pressure-can not damage seals. Sold in pairs only. Outer bearing: LM44643, LM44649. Outer cup: LM44610 with covers. One set of protector covers are included.