Premium Air Vent Filters - Made from high-quality and safe material, engineered to effectively purify the air you breathe from your AC units and heaters, also prevent dirt and other objects falling into the air vents Electrostatically Charged Air Filter - Self-charging electrostatic floor air vent filter, act as magnet to hold dust, dirt, pollen, smoke and unwanted particles in the air you breath everyday. Reduce your dusting and cleaning work every week! Experience Fresher & Relaxing Air - Unique air vent register filter not just purifying but you can drop a few drops of your favorite essential oil to the air filter to creates scented and relaxing atmosphere for your home and office Easy Installation - Simply insert these air vent filters into floor air vent registers and also for ceiling vent filter, fit to most standard 4x10 inch size vents. We recommend using vent filters in selected rooms as not to put too much stress on AC and heating systems Perfect Pack for Clean Air - Comes with 20 pcs of 4 x 10 inches air vent filter with 2mm thickness. Made from polyester, non-woven material, these heater vent filters can easily cut with scissors to fit smaller vents. These not intended to replace furnace filter