99.9% filtration with allergen, germ and odour reduction, electronic led controls, 3 cleaning levels including turbo, filter check reminder, on-board quick reference guide. For medium size rooms 155 sq.ft. Replacement filter (HRF-R1C) every year, pre-filter (HRF-AP1C) every 3 months. Auto shut-off timer (2,4,8 hours), energy star certified. 5 year limited warranty.