They work! Buy at least a couple and rotate them for much longer use.
These work! We have several, we use and recommend them frequently. My advise would be buy and use several, especially if you are blowing different types of smoke through them. They seem to last longer and work better if you rotate instead of using constantly. Also I have had better experience using each one for a specific product. Using for more than one type of smoke can make them smell awful after just a few weeks. If you rotate and use a different one for each type of product they last much longer than advertised. I have several that still work wonderfully after a year or more. These are awesome and they work! If you need them, buy them.  All colors work equally as well but a variety of colors breaks up the monotony :-)
Rating: 5 stars