The description for this mat says that it "Protects carpets up to-3/4-inch thick including padding" however I used this on carpet that was barely 1/2" thick and the wheels of my computer chair would keep sinking into dents in the carpet caused by how thin the material is. The mat provides basically no support for chairs on carpet.On top of all that when I received the mat it was absolutely filthy and the adhesive on the tape that was used to hold it together during shipping stuck to the mat.
If you want a floor chair mat this is better than nothing. This mat wasn't for sale in the store so a salesperson ordered it on-line. I made a huge mistake by not checking for spikes on the bottom of the mat; there aren't any! The mat slides on the carpet daily and jams itself someplace usually against the desk.
I must say I really enjoyed shopping at Staples....I had never been there before....The salesmen were very polite in helping me....Also answered all my questions....I'm hearing impaired and the salesmen was very understanding of me.I'm very happy with my purchase of my chair mat.Thank you!