Protect Plus Air 114241 Hvac Fiberglass Furnace Air Filter, 14" X 24" X 1" (Pack of 12) Fiberglass Size: 14" x 24" x 1" UL Class 2 Panel filter utilizing the purolator monobond concept of a one-piece frame sealed to the media using heat and pressure Fiberglass media is evenly coated with a gel adhesive to prevent finer particle migration