Where to find an N95 or high-filtration mask for Biden's 100-day challenge

The Biden administration has issued a mask mandate, requiring individuals to wear masks on federal property, and he's encouraging all Americans to wear them in public for 100 days. Face coverings are also required on planes, trains, buses and at airports, renewing questions about which kinds of masks provide the best protection against COVID-19, as well as where to find them. 

Link: https://www.cbsnews.com/news/n95-mask-mandate-where-to-buy-2021-02-01/