Cheap yes. Quality? questionable. You get what you pay for. It says right on the page, "for water ozonation only". This is not a therapeutic device. You should not apply ozone made from an air fed generator into the body directly. 200mg/hr would do considerable damage to the tissue.
Also, it can not be corona discharge AND Nikola Tesla technology. He did not make corona discharge generators after 1896, because they had short lives.