12x24x1 MERV 2 Non Pleated Air Filter Replacement Filters (Actual Size 11.75 x 23.75) - 3 Pack Sheet Metal/Adjustable Elbow + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 36" x 24" OR 24" x 36" duct opening (measured at the opening)

1/2" White insulation will give you a good R value of 3

Enhanced Filtration: Our filters are 25% thicker than competitors'

+ Product Details Size – 12" x 20" or 20" x 12" is the size for the duct opening measurement only

12x24x1 MERV 2 Non Pleated Air Filter Replacement Filters (Actual Size 11.75 x 23.75) - 3 Pack Sheet Metal/Adjustable Elbow + Product Details Perfect Fit+ Product Details 12" x 24" x 1" replacement air filters for your furnace, air conditioner, heat pump, or HVAC system (actual size: 11. 75" x 23. 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