The mat is not firm and the wheels of my chair sink into it a little making it difficult to move around on it. I ordered online if I had been in the store I would had selected a different mat
I work at my desk 7-9 hrs per day and purchased the matt to protect a medium pile carpet. Within the first few hours my office chair was sinking into the plastic. The entire matt also shifts with use (it has "teeth" but they are very short/dull points) and I have to rearrange the mat nearly every day. DO NOT WASTE YOUR MONEY - instead buy a sheet of plywood and have it cut to size you need.