Product review (4 stars): Does the job
True that these extenders aren't impressively beefy. True that they want to float up from vent, and that they may not be wide enough to cover entire vent if furniture placement requires they run the long length of the vent. But dry heat was wreaking havoc on a lovely French antique. This doohickey carries the air out from under the piece where in about an inch the air hits an area rug. Two weights placed on top of device anchor it and are hidden by the furniture "skirt". Weights not provided. I improvised. And I bought a sheet of magnetic vent covering material and cut it to fit the 2 inches not covered by this device. All this retrofitting took under five minutes. So. I'm satisfied. Problem fixed.