Didn't even rate the one star I gave it. This is not strong enough to roll a chair on. There are depressions in it after sitting on the chair for a while. Do not recommend this product.
It is too flexible. Wheels of chair sink into it and the chair does not move smoothly over the surface. Chair will not roll well at all. Mats I have had in the past were hard plastic and the chair wheels could move smoothly without sinking into the mat.