Using on a very low pile carpet. One hour after using the mat had permanent indentations in it where the chair was. Very cheaply made. Would not recommend.
If it is not on a "hard" or firm surface it will flex too much. If the carpet has any pile you get divots in the mat and the wheels sink in. It too thin for long term use on carpet.
Have an oriental overlaying wall-to-wall carpeting (a relic) and desk chair was always sticking. Don’t know why I waited so long to get the chair mat. It really helps greatly and enables chair movement freely.
I have a corner computer desk that sits on carpet medium plush. I HAVE to have a chairmat or the carpet would be ruined & I would not be able to roll my chair! This does the job.