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.