The mat is not firm enough and the wheels of the chair create indentations in the mat which make it difficult to roll the chair while sitting in it. I would not buy this mat again for use on carpet.
For a heavy fellow like me (230lbs) it has developed small ruts where the chair wheels usually rest. It requires effort to move out of the rut and effort to keep it from sliding in. Shifting the mat placement has helped but now new ruts are developing. Should have bought a thicker one.
TOO thin. On a carpet floor the wheels of the chair make indentations in the plastic and makes it harder to move than when it was just on the carpet by itself!!!