These moving pads are SUPER STICKY on the bottom. You can take it off still, but they stick on really nicely. They are also a nice felt so it doesn't vibrate, I have the same things under my case instead of the rubbers because 1 of them fell off and collected a lot of hair so I just replaced them all.
I personally love it because I like cleaning out the fans of my computer here and there so I just take it out.
You can get 160 of these pads for $5 at your local Home Depot. Just look for furniture pads.