Description said it was for carpet. I am using it on a firm berber carpet and the mat is not hard enough to stop my chair from making indentations in the mat. I literally have to lift my body up from the chair in order to scoot my chair casters out of the indentations. I would not recommend this product. May be OK on a tile floor but it has spikes on the bottom.
The previous one of these I had lasted 8 years so I got another. So far so good. It still gets indents from chair wheels the key is rotate the wheels from time to time so they aren't always on the same part of the mat. For a 195 lb guy plus a chair it works well.