Compatible Model: Our 211+ replacement filter are perfectly Compatible with Blue Pure 211+ Air Purifier. Please check your air purifier carefully to make sure it is the correct filter Effective Filtration: Our filter includes a 2-stage filtration system: Activated Carbon Filter and H13 True Hepa Filter. The activated carbon filter physically absorbs unwanted odors and fumes, such as cooking smells, smoke, and pet odors Premium Quality: Our filter are made of non-woven fabric and activated carbon, adopting advanced lower energy consumption and low-density structure technology; Use a 360-degree air intake, allowing you to breathe fresher air all the time Easy to Install: It is easy to install the 211+ air filter, no tools required. Simply take out and replace from your machine unit when needed In order to improve the performance of the air purifier, please replace the carbon filter every 6~8 months.