This oil seal fits onto the rotating shaft of the fertilizer spreader's metering or drive assembly. It prevents lubricant leakage from the bearing housing and blocks dust, fertilizer dust, and moisture from entering the bearing cavity. A worn seal allows contamination into the bearing, which accelerates wear and can cause shaft scoring or seizure. The seal's lip geometry matches the original housing bore and shaft diameter, so no additional shimming or adapter rings are required during installation.