I bought a similar mat for my carpet (from Staples) and it turned out to be too flimsy. The chair rollers sank into the thin plastic mat. So I returned it and upgraded to this "heavier" mat (again from Staples) which should be good for my 1/2 to 3/4" pile carpet. Unfortunately this mat isn't much thicker than the lower model mat and the rollers still sink into the mat and the chair can't move out of the depressions in the mat! Basically it's totally useless!! I'm tired of returning things to Staples so I've just given up and will eat the cost of the mat and try somewhere else... I can not recommend this mat to anyone.
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.
My previous chair mat had cracked so badly that pieces were about to break out of it. I received this one and rolled it out into place. I had to place some weighty objects on the edges to help flatten it out but it works fine. I does slip a little and I have to readjust it slightly from time to time but my chair rolls well on it. I have no complaints.
Right size for large based desk chair and high pile carpet. Time will tell if the product lasts. Looking for at least a 5 year ware before failure due to the expense.