25x20x1 MERV 2 Non Pleated Air Filter Replacement Filters (Actual Size 24.75 x 19.75) - 3 Pack Black + Product Details Size -

+ Product Details Size - 26"w X 18"h is the size for the duct opening measurement only

and other areas where baseboard-mounted return air grilles are required

+ Product Details Size - 4"W X 4"H is (for duct opening measurement only)

PRACTICAL DESIGN - The oval side out ceiling box is the best way to regulate airflow to install a manual volume damper in the duct run

you can't go wrong with this decorative grill

25x20x1 MERV 2 Non Pleated Air Filter Replacement Filters (Actual Size 24.75 x 19.75) - 3 Pack Black + Product Details Size -+ Product Details 25" x 20" x 1" replacement air filters for your furnace, air conditioner, heat pump, or HVAC system (actual size: 24. 75" x 19. 75") A unique combination of cotton & synthetic fibers gives you the most filtration and the least air resistance equals great air & easy airflow for your system. The non pleated design provides low airflow resistance while still effectively capturing dirt and particles such as standing dust, spray paint