The product description said this product would be fine with pile carpets. It is not stiff enough - so the chair creates dents in the mat. They are not permanent but with a rolling chair you are constantly stuck in the valleys that it creates.
This chair mat says for up to 3/4" carpet. I measured my carpet and it is less than that. The chair mat has dents in it from the chair and does not allow the chair to move freely while sitting in it. I will be replacing this mat.