Our BF35 Silver Carbon HEPA Filter Replacement Compatible with A-len BreatheSmart Classic BF35 Air Cleaner Purifier only. 3-in-1 Filtration system: The premium TRUE HEPA filter with 99.97% filtration efficiency ensures that the air you breathe is clean and healthy. The Activated Carbon Pre-filter helps to filters unwanted odors from pets, smoke, cooking, and filters large dust particles, which also helps to extend the life of the HEPA filter. What You Get: 2 x HEPA Filters + 2 × Carbon Pre-Filters Warm Tips: It's recommended to replace it every 6-8 months regularly depending on the air quality and frequency of use. Disclaimer: This product is an item that is designed to replace the OEM part. Any brand names or logos are the registered trademarks of their respective owners. Any use of any brand name or model designation for this product is made solely for purposes of demonstrating compatibility.