Abatement Technologies HEPA Filter Replacement Kit for Air Scrubbers & Negative Air Machines MERV 6 3 microns IEST compliant Healthy Air Filter:Five (5) Hypoallergenic (White) & One (1) Deodorizing (Blue) 3 microns IEST compliant non electrostatic — efficiency does not degrade over hundreds of hours of operation The zero bypass cabinet design ensures all air passes through the HEPA filter — no contaminated air can bypass around the filter media both filters should be cleaned once every two weeks and replaced every 12 months and maximize overall filtration performance 000 hours (approximately 1 year) of use under normal operating conditions