The 36" x 48" clear chair mat is the perfect size for my rolling office chair at my desk. I recommend buying one to save your carpet and making it easier to roll with a chair or have a stationary chair.
This is a replacement for a similar mat we had for a few years. It is not terribly rugged but works for our purposes. Not quite sure how to remove the tabs on the edge used to hang it in the store!!
Where this mat helped my chair glide easier over my carpeting indentations from the office chair wheels occurred within 2 days of receiving. This was very disappointing. I am now rotating the mat to help even out these dips.
I bought this mat to use in front of a home computer on what is apparently a low pile carpet instead of a flat pile carpet which I would call a no pile carpet. It will work for us because we won't be rolling around as in an office; but it is not stiff enough to keep us from denting in the mat with the chair's wheels but still protects the carpet.