Purchased this last month and placed on top of what I consider 'normal' residential carpet (non-berber carpet). This chair mat is not thick enough plastic to support my office chair. After just a few minutes of sitting the chair's wheels create 'divots' in the plastic mat and after a few hours creates a memory of where my chair was. Spend the extra $ and get a thicker mat if you are going to place on top of non-berber (low profile) carpet.
Delivery was amazing great. The actual product: my chair creates dents into the mat and it's difficult to maneuver my chair around. It's like the mat is just a bit too thin.