FILTRATION: With high filtration efficiency, the MERV 13 Pleated HVAC Furnace air filter effectively captures up to 90% of airborne particles from 3-10 microns particulates to help improve the overall air quality in your home. EASY TO READ AND USE LABEL: With a location on the label to let you easily mark the date you have installed the filler, helping you to know when it is time to replace the air filter. Locate the air flow direction to quickly install the filter into your HVAC system REPLACEMENT TIME: For optimal performance, replace the HVAC filters every 90 days, or sooner if the filter becomes dirty or damaged DIMENSIONS: The HVAC air filter's nominal dimensions are: 16 x 25 x 1 in. Actual filter dimensions: 15.5 x 24.5 x .75 in. CONTENTS: Included in the package are four (4) MERV 13 HVAC filters. At Filter Monster, we have over 25 years of experience helping customers breathe cleaner, healthier air with filtration solutions that combine performance, reliability, and value. Our Ultimate Defense MERV 13 HVAC filters are designed to provide extra protection against a wide range of airborne contaminants. The MERV 13 HVAC filters capture up to 90% of particles sized 3 to 10 microns, including common irritants like dust, pollen, pet dander, lint, and smoke. This makes them an excellent choice for households with pets or anyone serious about having the cleanest indoor air possible. What sets Filter Monster apart is our bold blue filter media, which serves as a quick, built-in identifier for MERV 13 performance. Seeing this bold blue media makes it easy to identify from other ratings during purchasing, handling, or installation—helping ensure you always get the right filter the first time. If you are seeking cleaner air in your home, or have to deal with wildfire smoke — blue is right for you. Affordable, resilient, and exactly what most homes need. Each package includes four (4) filters, providing up to a full year of clean air when replaced during the recommended time of every 90 days. For optimal performance, replace sooner if the filter becomes dirty, damaged, or if indoor air quality conditions demand it. Each filter also features a clearly marked label with an airflow direction indicator and a space to record the installation date, giving you peace of mind and helping maintain your HVAC system’s efficiency.