HIFESTYLE Oxygen Concentrator, 1-5L/min Adjustable Portable Oxygen Machine for Home and Travel Use, AC 110V Humidifiers - Green

One part of the device was missing. It is the cover to the primary filter. I'm getting by with duck tape. In addition the instruction book is quite difficult to understand because the translation is very very poor. It appears they used a computer translation program rather than pay for someone who actually speaks English. There are no instructions on what to do if you come up missing parts. Let's hope it performs well.