Don't buy it. It took me longer to open the packaging than I could mouse with it before I started to feel my index finger going numb. I am used to a smooth scrolling wheel; the wheel on this mouse moves in increments and is creaky & cranky. It can't possibly be good for the muscular structure of the hand and should come with an ergonomic hazard warning. On the other hand, if you're looking for 6 weeks off for a work-related injury...