Material: The trailer hitch lock is made of plastic and metal materials, which are strong, wear resistant, and impact resistant, ensuring long term reliability of the useFunction: Trailer hitch lock, professionally manufactured, easy to carry and store, can protect the security of your vehicle or boatEasy to Install: Coupler lock is an easy to lock system that can be easily installed without complicated tools, saving time and effortUnique Locking Mechanism: The tow hitch lock is equipped with a unique key that can be paired with a matching locking mechanism to prevent unauthorized individuals from easily removing the lock, which is more convenient for protecting your trailerApplication: This towing hook lock is only suitable for 2 5/16 inch trailer couplers, please check the size and make sure it is the right product for you Specification: Material: Plastic Metal Size Chart: 14.8 cm/5.83 inch Package Includes: 1 Set Trailer Hitch Lock with Keys Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.