I believe any size ball can go on any hitch, but of course any trailer can’t use any ball. I think you’d need to measure the “socket” of the trailer then purchase the correct ball (they’re labeled). We got ours from U-Haul.
You have to use the correct size ball for your trailer, but they also sell hitches that come with multiple interchangeable balls. Remembering from back in the day of owning jet skis.