DETROIT The effectiveness of masks can vary quite a bit depending on how they are made and what they are made of. READ: Confirmed US virus cases rise amid new global restrictionsN-95 masks are what health care workers use to protect themselves. But what makes those masks so much better? Local 4s Dr. Frank McGeorge spoke with the inventor of the special filter layer to find out and he shared advice for people making masks at home. Watch the video above for the full report