STRONG MAGNETIC: The Magnetic Exhaust Hood is made from thick and strong magnetic material, making it the only hood on the market that never come off, even over ceiling vents, for the greatest possible airflow!. SAVE ENERGY AND COST: Using these ceiling vent covers can effectively help you eliminate drafts in unused spaces in your home while significantly reducing the heating and air conditioning costs associated with controlling the temperature of these spaces. Keep the Small Things Out: With a sensible sealing design, this floor register vent cover keep small creatures crawling out of the vent, giving you peace of mind. It also prevents small items such as jewelry, crayons, blocks, snacks, small toys, pet food, and coins from falling into the vents. MULTIPLE USES: Our magnetic vent hoods are versatile and versatile, making them perfect for indoor or outdoor HVAC and RV use. Please use a magnet to verify that your vents are steel and not aluminum, wood, or plastic. Package Included: