Fantastic air purifyers and I have tried them all. Works as decribed. Only issue I have had out of the box was on one unit the lock button wont stay on(locked). Not a big issue since we have no kids. Didn't want to send it back for just that. I will wait til it needs other warranty work and get it fixed then. All the other buttons work great. Wife noticed a big improvement on dusting. We still both have some allergy issues even with these even though I upgraded to the filters with Silver. So they are great, but don't expect total resolution of your issues. At least we didn't.