I agree with the other reviewers - after a week there are already indentations from the chair. Okay for my purposes but if you are going to be at your desk for 8 hrs. a day giving this a lot of wear and tear you probably would want to upgrade to a more sturdy mat.
I was a little concerned that it would not hold up to being placed on a low pile carpet but it worked very well. My chair has four casters and I weigh approximately 175 pounds and because the vinyl is thick enough it does not appear to pose any problems punching through and making any holes.
I haven’t had this a week yet and the wheels from my chair has already sunken into the mat over the carpet I will keep watching to make sure the plastic doesn’t crack all the way thru creating a whole