Keep your air purifier performing at its best with this air purifier filter kit that includes 2 main cartridge filters and 4 activated carbon pre-filters. Compatible with Oreck Airvantage WK10002QPC / WK10002 / WK10004 and Airvantage Plus Pet WK10052QPC / WK10052 air purifiers, and compatible with Opti Max 94 / AIR94 models. Replacement for Oreck WK01234QPC and OptiMax AIR94 Filters. The main pleated cartridge filter helps retain up to 99.97% of particles down to 0.3 micron, supporting cleaner air by reducing common airborne contaminants such as smoke, dust, and pet hair. The activated carbon pre-filter serves as the first filtration layer to capture larger particles before they reach the main filter, helping extend cartridge life while neutralizing household odors from cooking, cleaning, smoking, and pets. Cartridge filter dimensions are 9 7/8 in x 9 1/16 in x 1 in, and carbon pre-filter dimensions are 9 7/8 in x 9 1/16 in x 1/8 in. For optimal results, replace main cartridge filters about every 6 months and carbon pre-filters about every 3 months; installation is simple and requires no tools. Disclaimer: This is not an Original Equipment Manufacturer (OEM) product, HQRP branded product is a replacement. All brand names and logos are registered trademarks of their respective owners. Any use of the brand names or model designations for this product are made solely for purposes of demonstrating compatibility.