Had to return it because the store does not keep it flat but rolls it up and puts tape around it to hold it. The tape leaves a thick glue deposit which is impossible to easily remove. This did not happen in the past when they stored them flat. To add to what I wrote above after several months the plastic breaks down into little very sharp pieces and the mat needs to be replaced.
I use the chair mat on my painted concrete floor because the rollers on the computer chair wear away the paint on the floor. The only bad thing about the chair mat is that the spikes on the bottom side wear down after a while due to the rollers on the computer chair.
product was as advertised. size was good for the location we needed to place it in. we haven't had this too long but it appears it will perform satisfactory for our use. main concern was to not damage new hardwood floor in an office in which we use rolliing chairs. This is the second one we have ordered. Both came from their warehouse. Both we pretty dusty and dirty. Had to wash them before placing on floor. The second one was pretty bent up but put it outside in sun on driveway and it straightened out. Other than that no complaints about the product.