Hoover A201 Air Purifier WH10301 Medium Room Air Purifier (150 CADR) recycles the air in a 15'X15' room (232 sq. ft.) nearly 5 times an hour Three-Stage Filtration includes an Odor-Absorbing Filter and a HEPA Type Filter for fresher air HEPA-Type Filter captures 99-percent of dust, allergens, pet dander and smoke from the air that passes through the filter Silence Technology is so quiet, it cleans the air on the lowest setting as you sleep Easy-Touch Controls includes 3 speed levels and a Check Filter Indicator Reset