The dependable difference for the casual user. Light weight, durable performance for moderate use on carpets up to 3/8'' thick. Easy-glide rolling surface provides effortless chair movement with any office chair. Studded design secures mat from moving while protecting carpet from caster wear, spills and heavy traffic. Free and Clear non-phthalate, non-cadmium formula promotes a healthy work environment while offering exceptional clarity and durability. Smooth beveled edge for easy carpet to mat transition. The chair mat will ship rolled up in a box, as pictured in the image. To flatten out the chair mat, please follow the following instructions: add weight to the corners of the chairmat. The chairmat will gradually flatten over several hours. The warmer the chairmat, the quicker it will lay flat. Try placing it in a warm room or near a sunny window for best and quickest results.