Filter King 16x20x4 MERV 13 air filters are built with a durable, moisture-resistant paperboard frame and pleated, standard-capacity 4-inch media to help your HVAC system run smoothly. Each filter is designed to last up to 90 days under typical residential conditions, capturing everyday airborne particles to support cleaner, healthier indoor air. The actual size of this filter is 15.5x19.5x3.75 inches, so be sure to measure your existing filter carefully to confirm the right fit. For easy comparison, the MERV 13 rating is roughly equivalent to MPR 1900 and FPR 10, making it simple to match performance across different rating systems. MERV 13 provides our highest level of filtration, targeting fine particles that lower-rated filters let pass through. It captures dust, pollen, mold, dust mites, bacteria, pet dander, smoke, smog, and even many cooking and odor-carrying particles. This level is ideal for sensitive environments, homes with respiratory concerns, or anyone who wants premium protection and cleaner, fresher-smelling air.