i have been fighting the noses of whitetails for most of 4 decades.Until last season I was convinced,just hunt the wind, thats all that works.. I still think one should only hunt the wind, but was absolutely stunned at the effectiveness of the ozonic units. Unfortunately, very few days offer me a pure wind, so i tried a ozonics unit at the recommendation of a friend. I was stunned at the number of deer that walked right under me with very suspect winds and even directly down wind. This happen on numerous occassions, not just once. It would be foolish to think that ozone works all the time, but it definitely helps a bunch.. Want hunt without it on those variable wind days..Take it for what its worth..