Gadgets on sites like eBay and Amazon is not going to make sure this purity level. Additionally, a prescription is necessary to get an oxygen concentrator. Be wary of these sellers and purchase oxygen concentrator only from licensed sellers. If you have any issues, give us a connect with at https://allhealthmarket.com/product/medical-supplies/portable-oxygen-concentrator-generator/oxygen-concentrator-machine-camping-use-oxygenator-driving-oxygen-bar-with-24-hours-battery-lasting-oxygen/