I spent several decades in the dry cleaning business. An Ozone machine works just fine in an enclosed place where it can filter the air. These gadgets they're trying to push for hunting are pure snake oil. They CAN NOT and WILL NOT cover your scent. DO NOT waist your money. There is no way in hell this toy can do what they claim. IF you were in a big plastic bag and this thing was attached to the only opening perhaps some relieve. Of course you suffocate before you got to the tree. LOL