I have carpet underneath a large office desk and chair and don’t want to ruin it. These mats are thick sturdy last a few years and are reasonably priced. If you have carpets underneath your desk chair this is a pretty necessary item. It has sharp grips on one side of it to adhere to the carpet (they won’t hurt it) so be careful when carrying it and laying it down. They are somewhat sharp but work well to keep the mat in place.