I love these! I have a lil corner in back of the house and nvr could use my resin printer because the fumes (voc)! I wanted to give these a try and man what a difference. My wife or kids nvr complained about the smell or fumes at all! Finally can use my resin printer again! Thanx bunches!

So when I first used these things I noticed that honestly it didn't work very well, I put them inside the machine like I've seen in pictures, I put them behind the machine next to the exhaust, did both things combined... it made barely any to no real difference to the smell that would linger in the room after about 20 minutes of printing.
THEN---!
I decided to get a redbull 6-pack box and I taped one open side to the back of the exhaust side of my printer and cut two square holes in the top just big enough to slide the filters inside so that they were forced to draw air directly and only from the smelly resin air coming from the printer itself, and THERE IS ZERO SMELL. I was honestly astounded, as I am writing this I have been running my printer for 36 straight hours that sits in a closed barely ventilated room while it's doing it's thing and there is literally zero odor in the room. And before you worry about the printer not getting adequate ventilation, it has not overheated whatsoever and is still able to get/exhaust plenty of air and nothing has been damaged. I will be buying replacement filters for these the rest of my life I am so thoroughly impressed I cannot speak higher of these things --- WHEN given a little helping hand to do its thing.

TLDR: These things really work but because they are using a piddly little computer fan that has next to no static pressure you really need to find a way to duct the exhaust into the intake portion of the filter units in order for them to really work great. The battery life is incredible too these things regularly last 10-12 hours on a full charge which is pretty amazing for the teeny-tiny battery they have in these things. A+ highly recommend.

I got two of the mini-air filter units to place next to the 3D printer that I am using at the time. The OEM charcoal filters have proved to be quite fragile. I dropped one of the units and the filter shattered! Getting multiple filters at once is needed by my clumsy self. The filters came very well packed and are perfect replacements! I look forward to using them!

More silent than the printer and eliminates almost all odor. Either the carbon filter has a slight odor or doesn't get all the resin odor but makes it tolerable rather than the straight resin smell.

These actually work very well to cut down VOC's and smells, but they quickly saturate and stop working.