I had ordered a different mat that over time cracked under my office chair wheels. I realized that I hadn't measured the depth of my carpet correctly (didn't include the pad) and ordered this mat to replace. This one is thicker and more solid and feels like it will last a long time. It arrived slightly bent but I flattened it with some heavy boxes in about a day.
This mat isn't heavy enough to be effective on carpet-it creeps forward and bends up against my desk every time I roll my chair forward so I am constantly having to pull it back.