Our Tier1 MERV 8 are pleated high-capacity filters constructed with 100% synthetic material. This material offers significantly higher particulate efficiency than typical poly/cotton media pleated filters, and captures the smallest and most troublesome airborne particles and allergens, such as particles that carry viruses and bacteria, pollen, mold spores, fine dust and pet dander. The combination of high efficiency, allergen reduction, and low cost make these the ideal choice for homeowners looking to improve indoor air quality on a budget.