The Dust Reduction attracts and captures particles such as dust, lint, and dust mite debris in your air. For optimum performance, the should be changed every 90 days. For MPR 300 Basic Dust & Lint Air , made by , helps capture unwanted particles from your household air to contribute to a cleaner, fresher home environment. Made with exclusive 3-in-1 technology, including an MPR 300 and MERV 5 rating, your AC 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 in your furnace, air conditioner or HVAC system. For optimal performance, change your furnace at least every 90 days.