HQRP 4-Pack Air Cleaner Filter for Hunter HEPAtech 30097, 30180, 30183, 30932 Air Purifiers Coaster HQRP&reg; 4-pack Air Purifier Filter plus HQRP&reg; Coaster; Effective Air Cleaning from smoke, dust, pollen, mold spores and pet dander; Should be replaced every 4 to 6 months depending on usage; Replaces Hunter 30928 filter; For use with HEPAtech Air Purfiers; Compatible with Original filter; 2 weeks DOA replacement warranty!