This chair mat arrived rolled up in a box I followed the directions for allowing it to come to room temperature. I left it in the room 5 days it never changed. Finally using both hands both feet and all my frustrations I was able to stretch it out but it would spring back with vengeance. I located and stage enough heavy items to weight it down and tried again. I was finally able to get it flat weighted down. I left it like that for 3 days. I was able to bring it to the area of my desk and place it. I still had to weight it down to stay flat. The weights have been off for one day and the sides are rolling back up. This is the only bad product I have ever bought from Staples and I am so disappointed. Do Not buy!
The description says it's good for carpet but it constantly sinks into the carpet with indentions. I'm 127lbs so I know for a fact weight is not the issue would not recommend for people with carpet.
The chair mat creates divots within a few minutes of sitting in the chair and makes it difficult to move around on teh chair rollers. I would not recommend this mat.