Keeping your trailer safe from thieves is a relatively easy task, one that requires a lot less labor than some of the tasks involved with hooking up and towing a trailer.
Receiver hitch locks are designed to fit crosswise into the receiver of your towing vehicle. They slide into a designated hole when the trailer hitch is hooked up and then lock in place. The pin slides between both the receiver and the trailer tongue inside it [source: Bear's Truck Accessories]. Typically, you remove a rubber cap at the end which hides the keyhole, insert the included key, and then turn to lock or unlock the pin.
To use most coupler locks, you must insert the key to remove the top bar, open the coupler, place the ball-shaped top inside, lock the coupler, put the top bar back on, and lock the bar in place. With the lock in place, no one will be able to hook up to your trailer.
For more information about using towing equipment properly and keeping your trailer and hitch accessories safe, please see the links on the following page.