Help buying a medical grade ozone generator.

Help buying a medical grade ozone generator.

Hi I have very little knowledge of this field. And am considering getting one of the devices on ebay listed by mygettingplace.

What should I pay attention to?

As far as I understand the only difference between this and a higher price unit is output and delivery mechanism. should I be concerned.

I'm only intending to use the device for insuffalation.