20 x 25 x 1 (4 Pack) Allergen Shield Plus Filter with Antimicrobial Layer. Also fits 2" openings.
OEM Part - Manufacturer #PF3P202501AT-4
This New & Innovative filter uses 3 Dimensionally layered Materials to capture more dust and allergens then most 'Paper' filters. The '4 Pack' is typically a 1 year supply.