Not suitable for many residential carpets or medium or thicker commercial carpets. 2" double-wheel castors dent the surface. That's fine if you don't want your chair to roll around. (??)
I've been using this desk chair mat for 2 weeks on medium pile carpet. My 5-wheel desk chair does leave divots while I'm working/sitting in the chair. So far the divots are not persistent; they level out in a few hours. I have not found the divots to be a significant issue as others have commented. If you want no divots using a desk chair mat on medium pile carpet one option is to spend 5x on a glass chair mat. For the price I think this vinyl mat works well.