The Mattek Anchormat chair mats are designed for use on medium-pile carpets with a thickness of 6-12mm including the underlay. They are made from durable twice-extruded PVC and keep your carpets protected from high-use wear. They also help to reduce the wear on office chair castors. This durable mat allows the user to move around easily while the rounded base grippers keep the mat securely fixed to the carpet.