[EFFECTIVE FILTRATION]: The HAPF600 filter replacement set includes 4 True HEPA filters designed to effectively capture airborne particles, including those as small as microns. Each set also includes 4 carbon filters with a thick design that fits securely into the holding tabs of the "B" style HEPA filter. Combined use enhances filtration efficiency, extends filter life, reduces unwanted odors, and improves indoor air quality, supporting a healthier home environment. [PREMIUM QUALITY]: This holmes air purifier filter replacement HAPF600 is constructed with high-strength non-woven fabric and features a pre-filter infused with activated carbon. Designed for low energy consumption and thoroughly tested by the manufacturer, it helps extend the lifespan of your air purifier and provides reliable performance. [PERIODIC REPLACEMENT]: This 4-pack HAP600 replacement filter allows for convenient periodic changes. Filter dimensions: HEPA filter 10.0 x 6.8 x 2.1 inches; pre-filter 9.2 x 5.9 inches. It is recommended to replace the filter every 3 to 6 months depending on usage and surrounding air quality to maintain optimal performance. [WIDELY COMPATIBLE]: This high-efficiency replacement filter is compatible with various holmes air purifier models, including HAPF600D-U3, HAPF600D-U2, HAPF600D-U1, Hapf600, HAP615, HAP625, HAP650, HAP675RC, HAP725, HAP750, HAP1625, HAP1650, HAP1725, HAP1750, BAP615, BAP625, BAP650, BAP1125, BAP1150, BAP1175, BAP1225, BAP1250, BAP1300, 106633, 106643, 106653, 106569, 106853. Color: As shown Material: Plastic Package Contents: 4 x HEPA filter, 4 x pre-filter Note: The package includes only the items listed. Image colors may vary slightly due to lighting and display settings. Measurement may vary by +/- 1-3 cm.