My 2nd choice for water filtration. Make sure you buy one with the additional flouride filters. I recommend this one if you can't install a RO filter or need an additional one for travel or emergency situations. You can put pool or pond water into this one in an emergency to make it safe to drink.
I researched air filters in depth and these are the best that I have found. Price but worth it if you are concerned with air quality in your home. These remove not only dust & pollen but also *chemicals*