Mat is large and works well on my office high pile carpeting. Was expecting longer "spikes" but we'll see how it lasts (previous mats have cracked within a year of moderate - two hours a day - use)
This came as described but is was just a little too flimsy for us. A heavier person will have their chair wheels sinking into this and making a dent and possibly not rolling smoothly. We are returning this item and ordering something more expensive and sturdier.