These things are garbage -- not worth the price! The last about 15 - 18 months and then get brittle and crack and eventually fall apart! Staples ought to get rid of this line and offer something of better quality.
This mat is too small for use on carpet because my chair is constantly rolling off the edge of the mat. It is also too thin and cannot carry the weight of me and my chair. I am hopeful I will be permitted to return it.
My last one lasted several years but cracked. This one feels better quality and is very easy to roll around on. I bought a second one for my Mom and she loves it (she's in her 80's and can't believe how easy it is to roll around on her office chair now).