Stop wasting energy and money! These Magnetic Vent Covers by Bond Helman help control the flow of air from heaters and air conditioners. Use the covers in the winter to keep rooms cozy warm and in the summer to stay comfortably cool. Simply place these covers over the registers in the rooms that are not in use and redirect the air flow to the rooms you are using. The result? Your forced air system will run more efficiently and cost effectively! To hide registers, these flexible oversized vent covers can be cut to size, painted, wall papered or textured to match your dcor. These vent covers work on wall and floor system vents. Please note: These covers are magnetic, so your vent must be metal for these to work properly.