Holmes LifeLong HEPA-Type Air Purifier with LifeLong Permanent Filter removes up to 99% of airborne particles as small as 2 microns from passing through it; Washable pre-filter helps capture larger particles and extends the life of the HEPA-type filter; Optional Ionizer setting naturally improves particle removal while freshening air; Three cleaning levels; Quiet operation; Recommended for rooms up to 170 sq ft (13ft x 13ft); CADR: 110