All air filter media restricts air to a degree. However, we've specifically chosen a fabric that's thin, allowing as much air flow as possible through while still retaining a heavy amount of dirt particles within the filter. Our fabric is supplied by professional manufacturers of air conditioner filters for major automobile brands. We believe our filters provide the best air flow to dust retention ratio for cut to fit filters compared to what's currently available on the market. SIMPLE INSTALLATION: 1. Measure vent cover. 2. Cut filter to fit. 3. Cut and adhere installation strips to vent cover. 4. Apply filter to register. 5. Change filter every 1 to 2 months or as needed. Our filters will install easily and work on vents located in any location including the floor, ceiling and walls. They can also be installed behind the duct grill. FITS ANY SIZE AND TYPE OF VENTS - This filter works with vents of all sizes. The roll can be cut to your desired size including popular sizes such as 4”x10”, 4”x12”, 8"x15" and 12”x14". Simply stick the installation strips to the edge of the air vent or air intake register and then place the filter on top. ADDITIONAL SPECIAL FEATURE - Our filter media can easily be peeled in half after you cut out the shape. This allows you to control the amount of airflow to a degree with the thinner, peeled in half fabric allowing more airflow. It also gives you twice the amount of filter fabric to use.