The professional 30-day plug-in air freshener for larger spaces. Dry fragrance refills contain 3-5 rimes more fragrance tan grocery store purchased plug-ins and freshens more space. The rotating plug works in any 3-prong outlet. The intensity button allows you to select the right setting, and there are no screws or tape needed to install. The high speed fan draws air through the charcoal filter, helping to clean the air for a better experience. Environmentally-friendly refills are 100% recyclable, do not contain acetone or propellants, and there are no batteries required.