COMPLETE PROTECTION- The car trailer hook will be protected to prevent corrosion or damage to the hook, and to prevent accidental grease on clothes. The tow ball cover can also be used as a small bumper when parking, so you can wash your car with confidence. HIGH QUALITY MATERIALS - The trailer hitch ball cover is Made of high quality plastic materials, waterproof, moisture-proof, tear-proof, wear-proof and corrosion-proof, strong and durable. PRACTICALITY- The trailer hitch ball cover can effectively protect the trailer ball from rusting and scratching when not in use, and extending the life of the trailer ball and drag chain. EASY TO USE- No other tools required, just push in, easy to install and remove. Truck ball protection cover with a fixed ring can prevent loss. WIDE RANGE OF APPLICATIONS- This trailer ball cap is suitable for all conventional car hitches, trucks, motorhomes, lorries container ships, trailers, cars, ships.