This product is specially designed for American heavy-duty trucks, semi-trailers and long-wheelbase freight vehicles. Made of high-performance modified rubber with integrated molding, it serves as a core protective component for constant velocity joints and drive shaft systems. It effectively blocks mud, gravel, water, oil and other road contaminants from entering the joint interior, prevents lubricant leakage, and extends the service life of drive shafts, CV joints, cross joints and drivetrain components. With excellent resistance to high and low temperatures, aging, oil and chemical corrosion, the product adapts to harsh working conditions including long-distance transportation, heavy-load vibration and extreme climates in North America. Featuring high elasticity and toughness, it flexes freely with the steering and extension of the drive shaft without cracking, loosening or leaking. It offers high matching fit for direct OEM replacement, greatly reducing vehicle maintenance costs and downtime, making it an ideal choice for the North American heavy-duty truck aftermarket and fleet operation.