Perhaps the 1/2 - 1" model. Rather obvious with the larger sizes, but they are not made to fit 1/2" pipe, are they? Looks to me like the larger two models are not designed to have the bottom flipped...???
Did you go to the link I posted? They are made for 1/2"pipe.
"Electricity is actually made up of extremely tiny particles called electrons, that you cannot see with the naked eye unless you have been drinking."