These new nanofibre masks from South Korea are similar but better than melt-blown N95 and KN95 masks. This new technology blocks smaller particles, is lighter weight and makes them reusable when sprayed with common ethanol for up to ten times. One masks is effective for 16 hours! At 2 hours/trip for shoppiing, appointments, meetings or outings a single mask can easily last all week. Then you just spray or dip with ethanol, let it completely dry and it is then reusable with little reduction in filtration effectiveness. No other disposable mask now available for the public has these advanced qualities.