GermGuardian RAC5000 3-in-1 True HEPA Air Purifier with UV Sanitizer and Odor Reduction, 28-Inch Tower (Certified Refurbished) Factory reconditioned 28 inch 3 speed tower is best used for medium to large rooms and CADR rated 125+ True HEPA Filter captures 99.97% of dust and allergens as small as .3 microns such as household dust, pet dander, mold spores and plant pollens. Charcoal filter reduces common odors from pets, smoking and cooking. UV-C light technology works with Titanium Dioxide to kill airborne bacteria, viruses, germs and mold spores. Only one single filter needs to be replaced every 6-8 months depending on the use of the product; Replacement filter is filter C (model FLT5000). To lengthen the life of your filter, a 4 pack of the carbon filters is also available (model FLT28CB4). IMPORTANT: Use genuine Guardian Technologies replacement parts to maintain product performance. 30 day limited manufacturer warranty.