*Money Saving 3-Pack* When you order this product, you will save $1.50 off of the normal retail filter price. You will receive 3 replacement HEPA air filters with carbon. This is the high efficiency filtering media, which is the heart of your air cleaner. This filter has a pleated HEPA filter and an activated carbon pre-filter in a cardboard frame for easy replacement. To maintain optimum efficiency, the HEPA filter should be inspected monthly and replaced at least every six to twelve months depending on use and air quality. If the pleated HEPA portion of the filter changes from white to brown or grey, it is time to change the filter. The activated carbon portion of the filter removes odors and traps larger particles such as hair and lint and should be replaced every three months. The filters may require more frequent replacement if the filter appears dirty to the point of blocking air flow through the equipment. Detailed replacement instructions are included on the back of the box. This high quality filter is manufactured by RPS Products. Save $1.50 when you order the 3-Pack.