Also nice with an eDox, means the bolts won't scratch the desk. I have the nuts on the top of mine as the head of the bolt is less likely to damage the pad.
ideally you'd want some sort of rubber matting.
This is so that you reduce the impulse of the rebound force on your wrists and finger joins.Show Image(http://www.cute-factor.com/images/smilies/onion/th_085_.gif)