Filter-Monster branded replacement compatible with Hunter 30915 air purifier filter. Engineered to fit Hunter air purifier models: 30010, 30025, 30040, 37025. 3-stage filter removes up to 99. 97% of airborne particles as small as 0. 3 microns in size including smoke, dust, pollen, pet hair and dander, mold spores and dust mites. Recommended to replace every 12 months for maximum efficiency, or more often depending on air quality & environmental factors. Package contains 1 replacement filter. Approximate Dimensions: 4-1/4 x 1-1/2 x 20-1/4 inches. Filter-Monster branded replacement compatible with Hunter 30915 air purifier filter. Fits Hunter air purifier models: 30010, 30025, 30040, 37025. Recommended to replace every 12 months for maximum efficiency, or more often depending on air quality & environmental factors. Package contains 1 replacement filter. Approximate Dimensions: 4-1/4 x 1-1/2 x 20-1/4 inches.