You can get 2 black magnetic ventilation covers for the ceiling, ventilation covers for indoor, home, office or indoor and outdoor places to maintain proper temperature control, enough to make your life better. our exhaust caps are made of soft rubber and magnets that are strong and enough to stick firmly to your vents, providing a safe and stable cover that can be used for a long time. install this magnetic cap on your vents to block most hot or cold airflow and help block noise between vents or building areas; These ceiling ventilation covers can enhance people's happiness in life. 12 x 12 inch register vent covers complete sealing and you can trim ceiling vent covers to fully fit your needs for vents, RV, home ceilings, vents, floors, walls, heater vents, etc. please test your vent with a small magnet and check the size before ordering, our magnetic vent covers are suitable for magnetic metal materials, otherwise they not stick; Not suitable for aluminum, wood, plastic vents. Size:12x12inch Colour:Black Material:Rubber+Iron Package Contents: 2 x magnet 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.