Item description from the seller Pleated Air Filters Replacement For Furnace. AC HVAC MERV 8 FPR 5 3-Pack New HDX filters are constructed of a durable, moisture-resistant frame with wire supported media for strength and rigidity. The wire-backed Pleated media offers a large surface area which increases the filter's dust-holding capacity and improves its efficiency. The air filter media can be charged electrostatically which means it attracts, captures and traps particles that would otherwise bypass the filter. The air filter's media is rated between a MERV 8 and 13, which is one component of the FPR Rating. FPR or the Filter Performance Rating, is composed of 4-measurements for classifying air filters. Every rating includes 4-elements: MERV rating, E1 efficiency, pressure drop and dust holding capacity. MERV stands for the Minimum Efficiency Reporting Value and measures how well a filter traps particles. The higher the rating, the few particles getting through. E1 efficiency explains how well it traps the smallest particles. Pressure drop measures how much energy the HVAC unit will use to force air through the filter. Dust holding capacity describes how much dust a filter will hold in its lifespan. HDX filters are easy to replace making change-outs quick and keeping indoor air quality at its optimal level while protecting your HVAC unit and allowing it to perform efficiently. HDX air filters capture and trap allergens, airborne contaminants and other particlesCreated to provide higher efficiency and better overall performance than standard pleated filtersWorks in furnaces, HVACs, wall vents and ceiling ventsItem represents 3 filters that will last up to 3-month, per filter, in a typical household environment and can be reordered through our subscription service Customer's Care:Please contact us before leaving Negative Feedback, Because We Always Take Care Our Customers, and Ready to Resolve their Issues Regarding Item. Thank You!