“They are ok. I haven’t noticed a big difference even though I have a house keeper come in every two weeks to clean my house good. Still more dust than I want as I have bad allergies, which is the reason I bought them. I have them dispersed through the house and where I sleep I have two. From the reviews I read there were great responses, so it makes me wonder if they were true or even real responses. Too much money for what I am experiencing.”