The paper filter is a kind of consume spare part for oxygen concentrator. It belongs to second level filter, can purify air for absorbing.
It is round design, in order to fill the air from all sides;
It is made of safe raw materials, and is safe to use;
After cleaning, can use again.
Pass ROHS test, be safe to use;
One paper filter can be used for about 1 year;
About 3000 hours later have a check and clean it, and then use it again.