I didn't realize that only one slide is locking, but it turns out that it probably doesn't matter much for most projects. I used it for a sliding platform in the back of my 4Runner, and it works fine. If the "cabinet" and "drawer" used with the slide are both well built, only one slide really needs to lock because the rest of the cabinet and drawer should keep everything square, as intended. Ends up that I'm happy I made the mistake in not paying very much attention to the listing....only operating one lock seems to be more convenient than having to unlock dual locks.