Best to call Uhaul and ask what is the suggested ball hight for the specific trailer you intend to rent or let them set you up with the correct ball mount when you pick up the trailer. Even though you could get away with a one size ball mount fits all approach it is better to match the mount to the trailer or at least to the trailer you intend to use most.Anyone have a Curt Class III and tow a Uhaul trailer? I want to rent the motorcycle trailer and I am thinking I should get the two inch drop ball mount?