As always, I get great products and customer service from Wayfair.  I went to Staples here locally and bought and returned 2 desk chair mats and they were not cheap, but the quality was.  As soon as we got them home to put down and use, my desk chair wouldn't roll on them and the chair made dents in the mats.  I searched online at other office supply stores here locally and they were made of all the same vinyl.  I purchased a smaller chair mat a few years ago and it worked great, but since my husband and I play games on facebook every evening, we needed a larger mat so we could roll both chairs on it with no problem.  This chair mat added with the one I bought from Wayfair before is of the same hard plastic material and works great on my thick piled carpet.  I would recommend it to anyone with carpet in their home office.