I was going to buy a Mounto, which are top-notch industry leading air scrubbers. In my case my plan was to modify mine a bit so I went with this cheaper unit which uses the same exact filters as the Mounto 500. This is the one to get for your hobbyist workshop. Don't be fooled by the Alorair or Abestorm 500 CFM units which use a 1 inch pre filter and a combo HEPA/carbon that is 1 inch HEPA and 1 inch carbon. The Mounto, and this Vevor unit, use a true 2 inch thick 16x19 HEPA filter and most importantly YOUR CHOICE of one or two inches of pre filters held in by convenient spring arms. The Vevor comes with one 1x16x16 MERV-10 and one 1x16x16 carbon honeycomb, or you can use a much more efficient 2x16x16 prefilter if you dont need the carbon! This is true of both the Vevor and the Mounto. I have to appreciate Vevor for designing their own product instead of copycatting Mounto. The larger inlet size is great for my needs. I love the fully removable and 4 side latched front case instead of Mounto's hinge design. The motor speed controller is terrible on this, the timer counts hours plugged in not hours running, and the replace filter sensor is actually just a safety switch that wont let the unit run if the HEPA cartridge is not in the unit. The motor controller is a cheap Triac feeding a chopped AC to a good 3 phase motor with capacitor. The full on position is not fully on and causes the motor to hum badly at all speeds, this eventually will degrade the controller or burn out the motor. I recommend professionals buy the real Mounto instead! Much better electronics! Now... The mods you want to know about... Better dust, fume, and VOC abatement - My use is for a studio workshop where no exhaust is possible. I use a 2x16x16 pre filter instead as a dust collection filter, and as you can see in picture, I then ducted mine to a large carbon canister post filter with 8 inch flex foil duct ... Just remove the outlet grid and spiral duct fits inside the outlet and again fits ins