A chair with rollers in any one spot for more that a few minutes on this chairmat develops a sinking spot. It is not thick enough for a chair with rollers on carpet. I weigh 160 and my chair is around 25lbs. That should not happen.
In just a week my chair has formed near permanent dents in the so-called carpet mat. The mat is clearly substandard and cannot be used on anything except a hard floor. Very disappointed.