Portable oxygen tanks require a medical device registration certificate. Portable oxygen respirators belong to the second category of medical devices and require approval procedures such as a medical device registration certificate before they can be put on the market. Oxygen tank, as the name suggests, is a tank used to hold oxygen. It is also called a portable oxygen inhaler and a small canned oxygen. It has the characteristics of high oxygen content, small size, easy portability and easy use. It is a new type of green health care product.