I bought this for my wife to use at her desk at home. It is just the perfect size--not too big and not too small. We have medium pile carpet and this chair mat seems to work great with it. It certainly will protect the carpet from wearing as the desk chair rolls around on it.
My 10 plus year old mat dried out and cracked where my chair sat so I replaced it with a new Flat Pile Carpet Mat. This is exactly the same size as the old one and it is an improvement in that it has has little nubs on the bottom which grip the carpet and keep the mat from sliding around. In another ten + years when this one wears out I will replace it with another like it.
If there was a zero star rating for this I would use it. It's a very badly made product. I used it for a week and it had several cracks and huge punctures in it. I returned it. DO NOT BUY THIS CHAIRMAT.
I think this product would be great if it was used as recommended on a flat pile carpet. I am using it on a high pile carpet and it still does the job but there are divots that I have to roll out of and I don't think it will last as long.