As soon as I put my desk chair (5 point ball casters) on the mat divots were created. I could not easily move the chair. I didn't even sit in the chair yet! This does NOT work for medium to high pile carpet at all. The advertised use is completely bogus.
Great value. Makes sitting at my home office desk easier to move around than just rolling my chair on my carpet. I need to get another one for my craft area table.
These chairmats worked out well for my office. I purchased 4 of them and they were easy to install no prep just remove from the box and install. Great economical product.
On medium pile carpet the chair creates divots that are so deep it's hard to roll out of them. They aren't permanent divots - but at the time you are trying to roll out they still inhibit your motion. The mat also creeps forward but I haven't had one before so maybe they all do?