Filtrete 21x21x1 AC Furnace Air Filter – MPR 700, MERV 8, 3-Month Pleated Electrostatic Filter, 4-Pack (Actual Size 20.81 x 20.81 x 0.81 in)

Improve daily air quality with a four-pack of Filtrete 21x21x1 filters

Designed to work with your heating and cooling system, the Filtrete Dust, Pollen, and Pet Dander filter uses electrostatic fibers to attract and trap particles as air moves through your ducts. The 3-month pleated design delivers ongoing filtration without frequent replacements, and the four-pack ensures you have a ready replacement on hand when it’s time to swap out the filter. With an actual size of 20.81 x 20.81 x 0.81 inches, these filters fit standard 21x21x1 slots while maintaining strong airflow.

For households that run a tight ship—from busy hallways to pet-filled living rooms—this filter aims to balance effective filtration with consistent airflow. While results can vary by room and usage, many customers appreciate the sense of cleaner air during pollen seasons, dust-heavy tasks, and everyday living. This is a practical upgrade for those who value a straightforward maintenance routine and a ready-to-use replacement when needed.

What you get in the 4-pack

• 4-pack of MPR 700, 3-month pleated Filtrete filters designed to help reduce the presence of common indoor particles
• Electrostatic fibers that attract and capture lint, pollen, dust, and pet dander
• System-friendly 1-inch filter with optimized airflow for compatible furnaces and air conditioners
• Guided by Filtrete’s 3-in-1 technology to trap particles while maintaining cleaner air movement

How Filtrete filtration works in daily use

• 3M-exclusive Filtrete 3-in-1 technology helps capture a range of particles while allowing air to flow through
• MERV 8 rating complements typical residential HVAC systems, targeting larger particles like pollen and dust
• Electrostatically charged fibers increase particle capture as air passes through the filter
• Designed to outperform non-electrostatic and simple fiberglass filters in everyday scenarios

Maintenance and setup tips

• Replace every 90 days for optimal performance in most homes, or sooner in high-dust environments
• Use the Filtrete Smart App to scan the packaging barcode and set a 30, 60, or 90-day replacement reminder
• Ensure proper seating in the filter slot to maintain consistent airflow and filtration efficiency
• Store spare filters nearby for quick swaps during busy weeks

While no filter promises specific health outcomes, many users note a perception of fresher air and a more comfortable living space as part of their routine maintenance. Filtrete’s approach combines practical filtration with easy-to-use features, helping you keep your HVAC system running smoothly without unnecessary hassle.