CONTAINS - 2 HEPA Filters & 4 Pre-Filters. Approximate Dimensions: 9-4/5 x 9-1/10 x 9/10 inches FIT - Compatible with Oreck WK01234QPC Air Purifier Filter Kit. For Oreck Airvantage WK10002QPC and Airvantage Plus Pet WK10052QPC air purifier models. True HEPA filtration removes up to 99.97% of airborne particles as small as 0.3 microns in size including smoke, dust, pollen, pet dander, mold spores and dust mite debris Recommended to replace HEPA filter every 6 months and pre-filter every 3 months for maximum efficiency, or more often depending on air quality and environmental factors Replaces OEM Part # WK01234QPC