MODEL COMPATIBILITY: The Filter-Monster H13 Air Filter Replacement is compatible with Medify MA-25 Air Purifiers. REPLACEMENT TIME: Depending on air quality environment and usage, it is recommended to replace the filter every three to four (3-4) months months to help ensure the Medify air purifier is running efficiently. DIMENSIONS: The Filter-Monster Filter-Monster H13 Air Filter Replacement is compatible with Medify MA-25 Air Purifiers. The air filters approximate dimensions are: 9.88” x 6.88” x 1.38”. Included in the package is two (2) replacement filters. Filter-Monster branded replacement replacement filter compatible with Medify MA-25 Air Purifiers. To ensure effective filtration, it is recommended to replace the filter every three to four (3-4) months or more often depending on air quality and environmental factors. Included in the package is two (2) replacement filter.