3 PACK - 18" x 22" x 2" AEROSTAR Filtration Group Pleated Air Filter (HR) | eBay
17x22x1 Odor Eliminator Air Filters - Only $20.40/ea.
HDX 17.5 in. x 29.5 in. x 1 in. Elite Allergen Pleated Air Filter FPR 12, MERV 13 61201.01175295 - The Home Depot
Filtrete 17.5-in W x 22-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