Chair mats are more than a piece of plastic under your chair. Chair mats protect floors... and a floor's warranty. Most manufacturers of flooring require use of a chair mat under a chair with casters, or else the warranty is void. Chair mats also provide a smooth rolling surface. Try rolling on a carpet. It takes 78% percent more energy to move a chair on carpet than on the smooth surface of a chair mat. ES ROBBINS chair mats provide the best quality, best performing ergonomic solution for your work area.