Nominal size 20 x 25 x 6 box type filter. Actual size (H) 19 3/4 x (W) 24 1/4 x (D) 6 . Space Gard is also known as Aprilaire Furnace Filters. No assembly required...no combs needed...filter just slides right in! Preassembled filter for easy installation! High-efficiency filter media collects small dust particles before they can collect on your coils. Superior frame strength utilizing double wall construction and die cut fingers. This product is listed and rated by Underwriters Laboratories as U.L. Class 2. All Nordic Pure pleated air filters are manufactured using a heavy duty moisture resistant beverage board frame. There is a metal mesh support grid bonded to the pleats for extra support. Our non-woven hypoallergenic and antimicrobial synthetic MERV rated air filter media will not support growth of mold or bacteria keeping your home healthier. As we say in the industry You have to move the air to clean the air . Our air filters use permanently electrostatically charged material that acts like a magnet to help dust cling to the air filter. This helps protect your unit home and family. For people suffering with allergies and other breathing issues choose our MERV 12 or higher MERV air filters to capture up to 98.9% of allergens pollens pet dander and other airborne particles. Visit our Brand Name menu to locate the genuine Nordic Pure brand replacement for your OEM air filters. Plus Carbon options: For MERV s 8 10 and 12 we now offer NEW IMPROVED Pleated MERV Plus Carbon Odor Reduction Air Filters for eliminating odors in your home or office. Our electrostatic MERV media and new carbon media are pleated together to form an exceptional dust and odor control air filter. The new pleated design provides 3 times as much carbon media per air filter for better absorption. The other MERV ratings available for this air filter have the MERV layer plus a flat poly Carbon layer. This option includes our electrostatic MERV media plus an added layer of polyester based media impregnated with activated carbon. In both Plus Carbon options the MERV media captures microscopic airborne dust pollen allergens mold spores pet dander bacteria and particulates carrying bacteria and viruses in the air for better indoor air quality. The high quality activated carbon media naturally deodorizes the air by absorbing and eliminating household odors that may come from pets garbage bathrooms smoke litter boxes or cooking. It also removes levels of concentration of gases (VOC s) as well as particulates in the air while maintaining excellent air flow properties. CLICK HERE for What is MERV information .