JORAIR4 Pack Replacement Filters Compatible with Pure Enrichment PureZone Mini Portable Air Purifier

tests conducted with purple air pa-11 aqi meter.1 these filters are ineffective out of the box, no comparison to originals they have only a minor impact on air quality and do not function is true hepa or even hepa filters should. they are too small to fit and air is passing through the gap and not being filtered, effectively making these useless.2 HOWEVER, by adding a little weather strip tape to the bottom facing portion of the black plastic, going 360 around the black circle of the base of the unit you can eliminate the gap and the results of testing after this are perfect: results were equal to or better then the original filters. I was able to test down to a perfect pm2.5 score of 0 on both laser sensors.moral of the story? spend 2$ on 3-4mm weather strip tape that seals the gap going all the way around the bottom black base and these work perfectly. dont put tape that is too thick or thin. the base cap should fit snugly but not be lose or need to be forced on to close.GL!