This the the new technology for tranny fluid changes. My buddy is a tranny tech at a local ford dealer and he told me they have a new machine that is connected to one of the tranny cooler lines and removes all of the old fluid even the stuff that's in the little cracks and crevices that would not drain using the conventional methods I questioned him about the filter and the machine back flushes it. He actually said it's better than doing it the old way.