Once I decided to purchase a couple of trailer hitches for my husband for his birthday I told my sister and mother in case they wanted to get him something to go along with them.  They were happy to get this information as they had no idea of what to get for my husband, however, once they learned that I was getting him hitches they immediately decided that they were going to be getting him trailer hitch locks .  This ended up working out well as my husband mentioned that he was going to need a lock when he opened his hitches so he was pretty happy when he opened the locks a few minutes later.