Revitalizaire Magnetic Vent Cover Extra Magnets Pack. Neodymium N35 1.3 Inch x 1.3 Inch x .08 Inch. 4 Pack - White

my magnetic register covers lose umph over time, and they can barely hang on where the pressure is highest, so these magnets are a life-saver! have to be careful when storing them, lest they bond together forever, but if you really need to boss your HVAC system around (as we do, with a 3.5 story modern house), this will be sure you succeed.

I've tried for years to get flat magnet sheets to block my heat vents, but they kept falling off. With these extra magnets, they're held in place with no slippage.

I like them because they work, and hold up my vent covers

I loved these they are very strong...

Weak weak weak. I used all 6 on my vent and the cover went flying. One of the magnets snapped in half when they fell. It’s not even a strong air flow as it’s the last vent in a decently long run.

Very weak, bought them to support vent magnet, useless.