Compatibility: Compatible with Hunter 30917 filters and can fit Hunter model numbers 30027, 30028, 30030, 30031, 30032, 30700, 30701, 30708, 36027, and 37027. 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. Quality Performance: 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 under normal conditions, and more often under harsh air conditions. Package contains one (1) replacement filter. Approximate Measurements: 10.25 x 4.25 x 1.5 inches. Filter-Monster branded replacement for Hunter 30917 Filter. Package contains one (1) filter.