Do these work?

[drfinalfantasy]

http://www.directron.com/tnpcs80.html

They are kinda interesting.....Do they work though?

[Hardrain]

Chances are that it works to some degree; as they say, your mileage may vary. I'd guess that since it doesn't decouple the fan entirely from the case (vibration still transmits through the screws), they are only really effective with unbalanced fans that cause significant vibration in their enclosures (the box part). I can see the value in dampening the body of the fan box, especially if you have big steel server cases like I do.

However, in your system with undervolted Panaflo L1As, the difference would be minimal at best. Your $5 would probably be better spent elsewhere, perhaps on a pizza, or maybe something from your local Steak & Shake. Just my opinion.