Filtrete™ 20x30x1 MPR 300 Air Filter made by 3M helps capture unwanted particles from your household air to contribute to a cleaner fresher home environment. Made with exclusive Filtrete™ 3-in-1 technology including an MPR 300 and MERV 5 rating your AC filter will help pull and capture lint household dust and dust mite debris while letting cleaner air flow through. Use a 3-month pleated 1-inch home HVAC filter in your furnace air conditioner or HVAC system. For optimal performance change your furnace filter at least every 90 days.