Product Detail 99.97% efficient at removing particulates as small as 0.3 micron 95% efficient in removing particulates 0.1 micron and smaller 400 cfm (cubic feet per minute) 4-Stage Filter Centrifugal fan with 3-Speed control . The "Austin HealthMate HEPA Air Filter HEPA Sandstone" is best product for you. We recommended Austin HealthMate HEPA Air Filter HEPA Sandstone