Designed to provide your home wide-spread coverage, the Alen A350, Paralda & T100 Whole House Pack gives you protection from high allergen and dust levels all over your home. Alen HEPA Air Purifiers feature Alen's advanced HEPA (High Efficiency Particulate Air) type filtration technology to purify and freshen the air in your home. Polluted air moves through Alen's unique, electrostatically charged HEPA type material that attracts and captures dust, pollen, pet dander, mold spores and other airborne pollutants. The Paralda includes Alen's anti-microbial Silver-Ion Technology, protecting the filter from harmful bacteria and microbe growth. The others feature Alen's Activated Carbon, reducing light odors and chemicals commonly found in the air from cleaning products, smoke, cooking, pets and other various household materials. Each air purifier's ozone-safe Ionizer complements the HEPA type filter by charging particles in the air, causing them to stick together and become more easily captured.