The chair mat indents from the chair feet or rollers creating these holes the stay in the mat and keep you from rolling around the mat. You actually have to pick up the chair to move out of the divots in the mat. Everytime you change positions of the chair new divots are created and they remain. This is very problematic and aggravating.
It is fine but I rated it a 4 because the sticker that held the paperwork I still can't get all of it off and it is really aggravating. And I don't know why I have to put a title in - your asked for the review of this product so I would think that could just auto-fill.
I was disappointed that if I sit for more than a few minutes in any one spot the wheels on the chair create impressions deep enought that I then get stuck in them. It's very difficult to roll out of them when moving sometimes I have to get up and move the chair. The impressions do go away in a short time once the chair is moved. My other issue is that this mat would NOT stay in place which amazed me since it had 3 table legs on it (from an l-shaped configuration). So several times a day it would creep several inches under the table and I'd have to take the chair off of it and fight to pull it back into place. I had been afraid to drill it as it is hard plastic and I thought it might crack a lot. I finally figured my daily struggle with it was worse than some cracks so I took the chance. Once it was in place I drew around each of the 3 table legs with a sharpie then took the mat to the basement for drilling. I first drilled with a small bit in the center of each sharpie circle then used a 1 1/8" hole drill to accommodate the 1" round table legs. Worked like a charm no cracks and nice smooth edges. Now the table legs keep it securely in place.