>> reporter: aaron collins, a self-proclaimed mask nerd, is a mechanical engineer with a background in aerosol science. >> there is significant improvement in the amount of aerosol that you'll be ix posed to when everyone is wearing an n95 and you're wearing an n95. >> it's worth reminding people why exactly they work so well. it has to do with the actual material. there are electrostatically charged fibers in here. it's not just filtering particles but attracting particles like a blanket might attract your socks in the dryer. also it works for air not potentially coming in but air potentially going out. one key thing about the n95 masks is you have to make sure that it actually fits really well. having these two bands around the back of your head and making sure no air is escaping around your eyes or your cheeks or your chin. studies have shown that cloth masks can have about 75%