Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: How do you know what size to purchase?
Document: I don't know how I ever lived without this mouse. I have one at work and then had to purchase another for home. It takes a bit to get used to it and to feel comfortable, but once you do you will find it more natural. We had people in our office that was opposed to using it, but once they got used to it they were very happy that they made the switch. If you are interested in ergonomic products this is a definite for sure!
I don't know whether it would be better with the medium version. Otherwise I find the grip size comfortable. The USB->PS/2 converter works fine, too. I run my mouse into a KVM switch using the converter, and it works on all my machines (Mac and Linux). This looked like the best ergonomic alternative to a standard mouse that I saw, and I'm happy I bought it.
At least I know that this mouse can take a beating!
This was a great purchase. I was suffering from a lot of pain in my wrist and this has helped me a lot. I have had this mouse only for a little over 1 month...therefore, take my review with a grain of salt.But this is definitely better than the regular mice.
All I know is without this mouse my hand is in so much pain that I just want to cut if off.
This mouse is great for those of us with RSI problems. I have had four of these mice over the past 6 years. Like others have stated, the tracking isn't great and it can break when traveling but in my opinion, the design makes up for those flaws.A worthwhile purchase.
This is my second purchase of this mouse. After having carpal-tunnel surgery on my right hand this mouse was suggested to me and boy am I glad my employer was willing to let me give it a try. The computer program that I use requires constant use of the mouse and if I have to use someone elses system and a regular mouse by the end of the day my hand and wrist ache.
I initially purchased this mouse because of tendonitis in my forearm (tennis elbow). If I use this mouse, I have no pain; if I use a traditional mouse, the pain returns. This mouse allows you to position your hand in a more natural way, so the muscle is not overtaxed by all the computer work. I purchased this one as a back up since my original purchase is at least 8 years old.
This is insane. I bought the wired 3M ergo mouse. After an exhaustive series of trial and error it does not seem to work on any mac with an Intel Core Duo processor.I just called 3M phone support and all he could tell me is, "I know it's crazy, but we have no support for this product beyond physical defects."
I received my mouse fast yesterday from Amazon. It has a big manual in many languages. It gave a url site that you have to get the software to operate the left button. The site  is not there for the driver. [...] . It just brings you to an apology page. Does anyone  know where it is located?. The books says. [...]Brian Nelson[...]bnelson@PartyTentCity.com
Answer: Here's the link to the 3M ergo mouse.  http://solutions.3m.com/3MContentRetrievalAPI/BlobServlet?locale=en_US&lmd;=1241455060000&assetId;=1180595739992&assetType;=MMM_Image&blobAttribute;=ImageFileIn case the link doesn't take work:  Large size for palm width between 3.5-5.5 inches ; small size is target for palm width between 0-3.5 inches.  To give you some ref. my palm measure 3.5in in width and I'm using the Large size.  The mouse is comfortable in my hand.