When I first saw this I thought -Why didn't I think of that! I bought one of those electrict heated mouse's and it doesn't keep your hand warm at all. The mouse is just hot!
This one actually keeps your mouse hand nice and warm - not hot or sweaty. At first I thought it would be hard to get my hand into the sleeve but it is really easy once you put your mouse inside the warmer. Great idea - simple - and works great. You should check it out at www.igmproducts.com