Blueair 203S HepaSilent Air-Purification System, Silver Energy Star air purifier with 3 speeds for rooms up to 175 square feet HEPASilent technology uses electrostatic and mechanical filtration SurroundAir system prevents annoying drafts; 5 air changes per hour Galvanized steel construction; 100-percent-recyclable filter media Measures 9-1/2 by 17 by 21 inches; 5-year limited warranty