I didn't see any instructions for it, but you have to remove the thin plastic films on all of the surfaces on the bottom of your mouse that come in contact with your mousepad. It's not obvious just by looking at it, as there aren't any tabs to facilitate pulling them off (there are seven of these). Presumably, they are there to keep them pristine during manufacturing or shipping. With them on, the mouse still works, but they cause just enough friction to be annoying.