UNIVERSAL COMPATIBILITY: 18x36x4 replacement air filters for your furnace. air conditioner. or heat pump enhance HVAC system efficiency and support a healthy lifestyle (actual size: 17.50" x 35.50" x 3.63") MERV 8 PERFORMANCE: Protect your home or business from pollen. lint. mold. and more with MERV 8 synthetic media (comparable with MPR 700 & FPR 5) that captures 90% of dust without restricting air flow LONG-LASTING FILTRATION: Electrostatically charged media with 8 pleats per foot traps more microscopic particles and lasts 3x longer than fiberglass models (replace every 90 days for optimal performance) SUPERIOR CONSTRUCTION: Easy installation beverage board frames with dual wire backing outperform flimsy cardboard designs by improving durability. preventing warping. and resisting extreme temperatures MADE IN THE USA: Built with industrial-grade. recyclable materials and proudly manufactured 100% in the United States for dependable indoor air quality that is trusted by millions of homes -