It really does work on any surface and its shape is wonderful - non of that thin middle that makes me grip it awkward. I know its wrong but I move from my wrist and push from the back of my hand and logitech get it right every time. So much easier to use than others. I can't stand them being thin in the middle as I feel strain in my and from gripping it tight. The thumb gap on the left is a little annoying, its a shame they didn't go for the regular rounded shape but still, its a breeze to use!