Of all the mods I have made to my equipment this undoubtedly has to be the best yet. I have been tackling the filter problem lately. Externals suck because the are messy and clog fast, old school bags that hang in the tank are okay, but clog and suck to clean. This mod works wet and dry, stays in the tank, is 95%+ efficient, never reduces airflow, is $65 and the filters are disposable. For my Scooter I cut a new 2" port in the side with a hole saw and cut off the top hose connection to the cyclone, 10 mins... done.