made out of shit i think, i've only tried them on a wooden desk and they glided horribly compared to hyperglides MS-3, get 8 pieces of steelseries ms glides for almost the same friction and zero pad scrapping like hoppan suggests http://www.esreality.com/?a=post&id=1852520#pid1852250

which it better the original version or the newer one?

newr=teflon$$$