REPLACEMENT AIR FILTER: Our Silver Carbon True HEPA air filter replacement is specifically designed for the Alen FIT50 air purifier. Insert our air purifier filters into the FIT50 and watch it clean 900 sq. ft. of air every 30 minutes. EFFECTIVE AIR PURIFIER FILTER: This Alen air purifier filter replacement is fantastic for better air in your home. The HEPA filter replacement features a 3-Stage H13 True HEPA filter that captures 99.9% of airborne particles larger than 0.1 micron. These HEPA filters are great for capturing household odors, pet dander, dust, and pollen. GENUINE ALEN REPLACEMENT FILTERS: This high-quality air filter replacement contains an ultra-absorbent activated carbon layer that absorbs harmful airborne particles and leaves you with fresh, clean air. LONG-LASTING PURE AIR FILTER: Our FF50 replacement air filters for air purifiers is manufactured to be long-lasting. Using our air purifier replacement filter, you'll get up to 12 months of pure air production in your home, apartment, or office space. TRANSFORM YOUR INDOOR AIR WITH ALEN: Here at Alen, we are dedicated to improving the quality of people’s lives by researching and developing cleverly designed and expertly crafted air purifying solutions that will utterly transform the air quality inside of virtually any indoor environment.