Bought this because it was a little thicker than most. Sadly it is so soft that just sitting there the chair wheels sink into the mat. When I move the chair the indentation slowly returns to normal. (I weigh less than 200 pounds.) Other than that it stays in place and the chair will move around as expected - once you get it out of the "hole" it created while sitting. For those who wonder it arrived unwrapped/"flat" - so soft it easily bends.
This mat only works with hardwood floors I guess. It is to soft the chair made an impression after the first use. So I decided to return it as soon as I can get a chance.
The only concern we had is that it is a bit softer than the previous mat for my husband's desk chair. He did not roll as freely using this mat. We solved the problem by swapping it for my older rigid mat which holds him well. I am easily accommodated by the new mat but I weigh 105 vs his 195 lbs.