As for other features, the Ergo Mouse is available in two versions: Large (EM550GPL) – which we’re reviewing here – and Small/Medium (EM550GPS). It’s a wireless device, too, so if clutter is a concern that’s a plus point. It also seems well built with a sturdy, solid feel and a smooth, soft-touch finish all over. On the underside is a battery compartment, an On/Off switch, and a button for syncing the mouse with its included USB receiver. Two AAAs are needed and some basic ones are provided in the box. offers something its main vertical competitors don’t – namely, a size selection. There are only two different sizes available, large and small – which is somewhat limiting, but still beats one-size-fits-all. I found the large model a bit too large for my sizable hand, but I’m sure the small would have been wrong for me in the other extreme. I think 3M could improve in this area by following the example of the Handshoe and offering more than just two sizes. Thumbthing to think about

Giving the Ergo Mouse a go, the benefits of this more relaxed hand position were immediately obvious to me as the reduction in pressure on the heel of my hand alleviated the niggling pains I get there. Meanwhile the more natural wrist position reduced overall tension in the general forearm area. Even my finger pain was reduced. Quite simply, this thing definitely works when it comes to reducing pain. Sadly, it’s somewhat less accomplished when it comes to most of the other traits we look for in a good mouse/pointing device.