The mat is okay but I can tell that it won't last very long. After the first week there were serious indentations where my chair sits and rolls the most. I can see places where it could crack. If you want a great mat to last a long time you'll have to pay more money.
Chair mat is low in price which is why I chose it. However I should have spent the money and went with a more expensive durable product. I type all day and this mat just is not strong enough to hold up for the long-term.
Had to lay mat outside in the sun to get it to lay flat. The library-like chair I use does not slide very well but this mat does protect the carpet well.