The problem is packaging, to get the required CFM without robbing power would require two 8-10" diameter canisters. One issue I have with UMP & PRC is they don't list CFM specs (I highly doubt they've done the testing). I absolutely love Donaldson systems but here again they are large to get the required CFM, was just looking at their specs a few min ago LOL. As always, I'm over thinking shit.....