*Money Saving 3-Pack* When you order this product, you will save $3.00 off of the normal retail filter price. You will receive 3 genuine Aprilaire high quality replacement air filters. The high efficiency filtering media is the heart of your air cleaner. To maintain optimum efficiency, the filters should be inspected quarterly and replaced at least every 12 months. The filters may require more frequent replacement if the filter appears dirty to the point of blocking air flow through the heating/cooling equipment. Detailed replacement instuctions are included on the back of the box. When replacing the filter be sure to keep the pleat spaces as they can be used for the life of the mechanical air cleaner. This high quality filter is manufactured by Purolator. Save $3.00 when you order this 3-Pack.