Chairmat works great. We just had an antique British Bankers' Chair refinished and the mat keeps my dear husband from ruining our carpet. He comes into the den with dirt on his shoes and also eats at the desk. I am thrilled. Carpet is now fully protected.
Bought three of these and all three only lasted 7 - 8 months before we threw them out. The plastic cracked in several places which made it definitely NOT a smooth rolling surface.