This set contains two Deodorization filters (thin black plastic sheets) and one HEPA filter (thick white sheet). Since the deodorization filters are supposed to be replace every six months and the HEPA filter once a year, this set is good for a full year.
The installation is easy enough, but the manual is a bit inscrutable at times (like so many others of course). I've read that many customers complained about a bad smell with these replacement filters. When I first unpackaged the replacement filters, I didn't small anything bad, but once I installed them and started the unit, I also caught a whiff of unpleasant small. After running the unit in a closed room with a window exhaust fan for a day, the smell was completely gone, so I'm only deducting one star for this.
f you have lost the manual or - like me - find the manual near inscrutable - here's a quick recap on how to replace the filters (for my own future benefit as well as for anyone else's):
1. Take note on the unit, which filter(s) you are supposed to replace. Turn your unit off and unplug it.
2. Open the front cover by pulling at the top of it, then lift it out of the bottom recess.
3. On the top of the inside there are two clips. Press them down and lift out the Pre-filter. On the back of the pre-filter is tucked in the Deodorization filter. Remove that filter and discard it.
4. Since the Pre-filter will likely have a lot of dust in front of it, it needs cleaning. The manual recommends using a vacuum cleaner for this.
5. Remove one of the new Deodorization filters from its plastic cover and tuck it in on the backside of the Pre-filter. There are some plastic latches that are supposed to hold it in place.
6. If you are supposed to replace the HEPA-filter, lift the old one out of the unit with the plastic straps, remove the new one from its plastic cover and put it in the unit. Caution: Make sure the plastic straps (which have the word "front" on them) are facing you and the arrow on the side of the filter is facing toward the unit! Discard the old filter.
7. Reinstall the Pre-filter (which the Deodorization filter attached to its back) by putting the bottom latches into the proper nook, then push the top in until the top clipslock back to the unit.
8. Reinstall the cover of the unit, again bottom first, then push the top clips in.
9. Plug the unit back into and turn it on. To clear the replacement indicator(s), press the reset button for 2 seconds. This will clear all the replacement lights that a re currently active and reset the corresponding timers. Timers, whose lights are not on are not affected. If you changed the filter(s) BEFORE the replacement light was one, consult the manual on how to reset the corresponding timer in that case.
Avital Kelman
Bubble Metropolis 
M&T