Product review (1 stars): It works great to prevent dust accumulating on your fan!
It works great to prevent dust accumulating on your fan, because your fan won't move air with it on.

Great price, great idea, poor execution. I bought it for a 12" fan and even on the smallest size it's supposed to fit, there's no way it would actually have prevented dust coming in the back side, as much space as it left around the motor. A bigger fan would have made the problem even more obvious. And yet, it reduced air movement so completely that there was no point running the fan at all. I literally turned my fan off for two days, because it was just making noise and not doing any work, before deciding to attempt to return this product.

If you're one of those people who needs a white noise machine and can't sleep without their fan on, this is a great fix for winter, when you might not want air actually blowing drafts around. Other than that, it's totally pointless. (And seriously, just get a white noise machine.)

This is the first negative review I've ever posted in fifteen years of buying stuff online... Just, don't buy this. I wanted to love it, but there's nothing to love about it. Just resolve yourself to the fact that you will have to take your fan apart every couple of months and clean it and enjoy the breeze.