Filter King Air Filters 21.5x24x1 4-PACK MERV 8 HVAC Pleated AC Furnace Filters Air Purifier Replacement Filters for Clean, Healthy & Fresh Environment MADE IN USA 21.5x24x1 Inch (Pack of 4) - Walmart.com
Filtrete 16.5-in W x 21.5-in L x 1-in MERV 11 1085 MPR Allergen Defense Extra Electrostatic Pleated Air Filter (2-Pack) in the Air Filters department at Lowes.com
16.38×21.5×1 AC/Furnace Air Filter (Made by American Filter Company™) Made in U.S.A – American Filter Company