3-STAGE FILTRATION: The -h128 replacement filter has a three-stage filter design. The first pre-filter layer filters large particles such as pet hair and fur. The second H13 HEPA filter reduces 99.97% of dust, PM2.5 and dirt in the air. The third layer of activated carbon filters removes odours. A comfortable and safe environment for your children and family REPLACEMENT CYCLE: The use of a new filter can improve the efficiency of your air purifier, thereby ensuring fresh and safe air in the room. It is recommended to replace the -h128 h13 filter every 6 months. EASY INSTALLATION: air in a few steps 1. remove the filter cover 2. unwrap the new -128 filter 3. place the filters into the air purifier 4. replace the filter cover Colour:black Material:Filter cotton Package Contents: 4 Pack * HEPA Replacement Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.