For people with large hands (in my case ^^) This "whelk" is really great. I can say goodbye to sore wrist and forearm due to a too long use of mouse ... there, the arm does not move at all. the underside of the wrist based on the rubber support provided with. The mastery of this gear comes very quickly pushes for left click; auricular to right-click and ring for the scroll ring. I still left mouse connected (for my wife ^^) and there is no conflict between these two devices that ultimately serve the same purpose. My "whelk" and immediately recognized by Windows 7 that does it all (you plug it into the first available USB port and that's it!). The operation is very precise. If you find that the pointer moves too fast on your screen, do not worry everything is configurable.