The Ball and Ring Trailer Hitch Lock for Heavy Equipment can be used to provide protection for your trailer. It fits on any trailer using a ball or ring-type hitch. Your trailer can't be hooked up and taken away because the lock occupies a ball placement. Construction workers and landscapers will greatly appreciate this lock because they use trailers on the jobsite. Comes with barrel type keys. Keyed Alike: The same key will open multiple locks. **Only order if ordering more than one unit