3M™ 604-6PACK Exhalation Valve Filter, 604 - Modifies 6000 series half-masks to provide source control for airborne viruses | International Safety
Filtrete 14-in W x 25-in L x 1-in 1900 Smart Premium Allergen, Bacteria and Virus Electrostatic Pleated Air Filter in the Air Filters department at Lowes.com
Filtrete 18x30x1, MERV 12, Allergen, Bacteria & Virus HVAC Air and Furnace Filter, 1500 MPR, 1 Filter - Walmart.com