I purchased this chair as a previous cloth back & seat one was showing signs of wear and the plastic mesh seat/back appealed to me and were very comfortable especially the lumbar adjustable support feature. I was disappointed to learn that the chair is sold with hard tread casters for use ON CARPETED AREAS. If you intend to use it on a hard surface or chair mat you must purchase soft tread casters & install them instead of those provided. I have seen what casters do to carpets and would never use this or any other such chair without a mat. I would think that those provided would be for hard or mat usage and if one intended to use on a carpet surface those would be the ones that would need to be purchased for use.
This chair is super comfortable having to sit in it 6+ hours a day. It was easy to put together and it came quickly from Staples. I may buy a 2nd one for my home.