Let me start by saying these vent extenders are a total lifesaver for anyone with floor vents hiding under furniture. I tested them under my couch and bed, and WOW – the difference in room temperature was noticeable within hours. No more wasted heat getting trapped!

The trapezoidal design really does optimize airflow better than those cheap plastic ones at big-box stores. I love how it extends from 17" to 33" – perfect for my oversized sectional. The 1.5mm thickness feels sturdy yet flexible when adjusting.

Now let's talk magnets... They're strong enough to stay put (my cats haven't knocked them off yet!), but like other reviewers mentioned, one of mine arrived with a loose magnet. A quick dab of super glue fixed it permanently. Pro tip: Buy some extra neodymium magnets as backup.

The real magic happens when you see your heating bill drop. My west-facing living room used to be an icebox because the vent was completely blocked by furniture. Now the warm air actually reaches ME instead of just roasting the underside of my couch.

Two minor drawbacks: The magnetic attachment lifts the sides slightly (some air escapes), and the plastic could be thicker – though this makes it easier to adjust than heavier competitors. For the price though? Absolute steal compared to that $50 single extender alternative.

Final verdict: If you have pets/kids or just hate wasting HVAC energy, these are worth every penny. Just keep some glue handy for magnet reinforcement!