Air Quality Improvement: Activated carbon helps reduce household odors such as cooking, cleaning and pet odors Compatibility: Replacement pre-filter that is compatible for Whirlpool Air Purifiers including models APT30010M, APT40010R, APT42010M, APT50010M Compatibility: Replacement compatible with Whirlpool 817500 Maintenance: Recommended to change every three (3) months, or more often in harsh environments, for maximum efficiency Approximate Dimensions: 20 1/2 x 4 3/4 x 1/8 inches Filter-Monster branded carbon pre-filter replacement for compatible with Whirlpool Mini Tower 817100 Pre-Filter helps reduce odors and maximize filter life.