These are a few tiny slots at The underside of the casing that need to be open up instead of blocked, to allow air to enter the unit when inhaling. The odor is a fog of citrus and natural earth circumstances that actually subside to the place and inspire you. It resembles breathing sweets. Unf

I actually like mine, using the interesting mint and I have not had only one craving for an genuine cigarette. An acquaintance had equipped mine as I used to be unexpectedly hospitalized for 8 days and it surely received me above my hurdle while confined. I might endorse this for anybody interested.