25 Air Purifier Replacement Filter for MA Series Air Purifier 25 S1/W1/B1

25 Replacement filter fits for 25 air purifier S1/W1/B1 models. Your unit has a filter on each side, both filters should be replaced at the same time. | 3-IN-1 FILTRATION: 25 Filters are made of 3-in-1 filtration systems including Nylon Pre-Filter, Pleated Filter, and Activated Carbon Filter. | HIGH-EFFICIENCY: The premium granular activated carbon filter physically absorbs dust, smoke, other volatile gases, pollen and fine pollutants. Suitable for a wider range, it is a good choice for families with smoke problems, pollen problems, pet odor. | COST EFFECTIVE: Package includes 1 Set (4 filters). Fully meet your needs for the replacement of 25 filter | EASY TO INSTALL: Installation is easy with no tools required. We recommend replacing the 25 air purifier filter every 3-6 months for optimal performance, depending on usage and environment.