I bought this flat pile carpet chair mat to go on tight firm flat pile carpet in a dental office under a Staples work chair in which I sit for several hours daily. I weigh 185-190 pounds. The chair's 5 wheels literally sink into the mat when I sit down; it is that flexible and soft. Rolling from a computer location to a file cabinet or records shelves in the office requires literally pushing the 5 wheels out of 5 depressions in the mat which takes negligible effort but should not need to be done in the first place. This mat does not compare with mats I have had before for similar carpets but today's choices appear to be much more limited; unless things change when this mat wears out I might consider going without a mat.
Although this says medium pile carpet it moves across the carpet as I stand walk or sit in my chair on it. I had to put my desk on it to keep it from moving. The chair casters do push in a bit but it does recover. I think it should be rated for low pile carpet. My carpet is a cut and loop lower pile with a good firm pad. I guess it's not that low of a pile.
Arrived at scheduled day. Good sturdy plastic mat. I recommend this mat. Check the carpet-mat thickness table before ordering. The table is very useful as it guides which mat type to purchase.