Compatibility: Compatible with Filtrete D filters. Air Quality Improvement: Filtration is rated H13 and removes up to 99.97% of airborne particles as small as 0.3 microns in size including dust, smoke, pollen, pet hair and dander, mold spores and dust mites. Airtight Seal: Foam gasket seal for high performance filtration directs air through the filter and keeps air from escaping around the sides. Maintenance: Recommended to change this filter once every twelve (12) months and more often under harsh air conditions. Approximate Dimensions: 13.5 x 11.75 x 1.5 inches Filter-Monster branded replacement for Filtrete D Filter removes smoke, dust, pollen, pet dander, mold spores and dust mites from the air.