I have gotten this chair mat in the past. They are great to start but eventually start cracking where the wheels of the chair move over it. But so far - so good.
The mat is not stable on carpets. In a short period of time the mat will move forward because of the desk chair being moved back and forth forcing you to pick up mat to move it backwards.
This mat was pretty thin for use on any kind of carpet. The chair legs sink in the mat "moves" and the edges curl. Walking past I cut my foot on the edge of the mat where it was raised up. I would not recommend this mat for any kind of carpet situation.