Bearing oil seals are usually used in heavy machinery such as trucks, trailers, and agricultural machinery. The combined design and multiple dust-proof lips can prevent oil and sand from intruding, and the spring of the main lip can be tightly combined with the bearing, which is less likely to damage the shaft. If there is oil leakage, you only need to replace the oil seal, and the card's oil seal is more likely to damage the shaft. Commonly used in power machinery, large trucks, coupled vehicles, large trailers, etc.