4 Pack Model 15 Replacement Filters Compatible with Air Puri-fier MA Series, H13 True and Activated Carbon, 3 in 1 with Pre-Filter

COMPATIBILITY: These model 15 replacement filters, compatible with the MA air puri-fier 15 series S1/W1, measure 9 3/4" x 5 1/8" x 1" (9.75" x 5.125" x 1"). The performance of the filter cartridge will deteriorate over time, or even become ineffective, causing secondary pollution. We recommend replacing the filter every 3-4 months or when the air purifier's replacement cartridge light turns red, please replace the cartridge in time | 3-STAGE FILTRATION: These model 15 replacement filters feature a 3-stage filtration system that more effectively eliminates dust, impurities, and odors from the air, filling your room with fresh, non-irritating air | FIRST LAYER PRE-FILTER: The pre-filter is made of saturated polyester material, which is resistant to bending, oil and acid, alkali, etc. It can pre-treat the air, effectively intercept 10 PM particulate pollutants such as dust, hair, and fine debris, and prolong the service life of the filter | MIDDLE LAYER TRUE H13 FILTER: These model 15 replacement filters made of electrostatic electret composite filter paper material, it can capture 99.9% of the air particles as small as 0.1 microns, and more effectively remove dust, and PM2.5, so that breathing is easier | THIRD LAYER ACTIVATED CARBON FILTER: These model 15 replacement filters made of coconut shell activated carbon, which can effectively remove formaldehyde and odor, making the air fresher