Stop Thieves From Stealing Your Trailer. Receiver locks keep your towing system and its components together until you unlock it. In fact, no one can unhitch your trailer when using a receiver and coupler lock combination. Reese Towpower® manufacturers several styles of receiver hitch locks to accommodate every class of towing equipment. Finishes include stainless steel, chrome and black nickel, and all locks come with two keys. Most designs also come with a rubber cap to keep dirt out of the key opening. For added security, our Professional line of receiver locks features a virtually pick-proof square key design.