Tow ball drop-down extension

I'm trying to find some sort of quick release extension that fits over a standard 50mm tow ball in order to drop the height by about 4 inches. My 90's standard tow ball is too high for my trailer (it's miniscule) and I wouldn't like any fixed drop-down plates (like dixon-bates for instance). does something of the sort exist? and if so, what are they referred to?

never seen owt like that, cant see how it wold work either...
If its just a small trailer, cant you pack up the hitch so the hitch on the trailer is higher, failing that the only options are a dixon bate type or a drop plate. unless you want to spent a few pennies on a receiver hitch.

Thanks. I'll just pack up the hitch. What is a receiver hitch?

Any pic's of the tow bracket / hitch mite help