Magnetic Vent Cover - Sticks to steel registers only. Our air vent cover can only be used on steel air vents. It cannot be used on aluminum, plastic, or wooden material air vents. The magnetic ceiling vent cover can stick tightly to your floor, ceiling, and wall vents, and needn't fear dropdown. Material - Air vent covers for the home are made of a strong anisotropic rubber magnet, and the is covered with white PVC, which can provide excellent magnetic flux and 100% protection. The holding strength of magnetic register vent covers is stronger! Size - The size of magnet vent covers for the home ceiling is 5.5x12inch, which fits most standard air registers, and is also easy to cut, supports cutting the size to suit your special size air vent. Energy Saving - With this air vent cover you can close registers in unused spaces in your home, and reduce the heating and air conditioning costs associated with controlling the temperature in those spaces. Save energy, save money! More Comfortable Home - The register cover stops your unwanted from passing through the vents, and reduces the transmission of noise through the vents. It also prevents little things and other harmful substances from passing through the ductwork, creating a comfortable environment in the home. Quantity:3 Pack Colour:White Material:rubber Size:14x30cm Package Contents: 1set * magnetic air vent covers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.