Initially ordered the larger one which took up way too much space. I have just put in new hardwood floors and wanted to ensure the wood was not destroyed by my office chair wheels. This does the job more than adequately and it was a good price.
True - if you are going to use it on a thicker carpet at home for example This is not the perfect chair mat - The cleats are too short and the chair will leave "dents" where its wheels are and where you sit. However the dents pretty much bounce back. The mats made for thicker carpets are twice the cost so this solution certainly works if you cannot afford the others. Rolling an office chair around is much easier now with this mat than without.
Despite being a more expensive chairmat than some other Staples models this "lifetime warranty" product showed stress cracks in about 10 months and started breaking into chunks a couple of months afterwards. When I contacted Staples about the warranty they referred me to the company which manufactures the chairmats for the Staples imprint. In order to get a replacement for the mat I was required to cut a 6 inch by 6 inch square from the old chairmat (hint: it will take power tools) to send in with all of my documentation...after which they'd take up to a month to send me a replacement. I did the cutting but it was a hard and potentially hazardous job. But I couldn't wait a month for a replacement chairmat so had to buy one of another brand for immediate use - and will stockpile the replacement if and when it arrives. I can't help but think these policies are deliberately intended to discourage people from pursuing their warranty coverage on a product that simply doesn't hold up to normal use and I'm disappointed.