We got this for a low/med carpet thickness with an office chair that has wheels. Within a few minutes of sitting in the chair there were visible indentations from the wheels. It's better than not having anything on the carpet. I also purchased a more expensive Floortex one and it is MUCH better quality than the Staples one. This one is just good enough as long as you regularly move the chair so the indentations to stay in the same place.
Chair sinks into mat after awhile so you have to try to roll past the divot created. (I am not that heavy). The mat does scoot around on the carpet though most every mat I have had does so. Otherwise the mat works okay.
Chair mat blends nicely with carpet…but after two weeks in place it already has indent marks from the wheels on the chair bottom…can’t help but to wonder about longevity.