Perfect chair mat!  I have an L-shaped desk with carpet for flooring and all the other types of chair mats were mostly for hard type floors or would not fit. Found this hexagon shaped mat made especially for carpet and it works great !  Just the right size as it fits the 5 wheels on my chair and fits between the desk opening. I can now sit down and easily move my chair back and forth as needed. The plastic is semi-rigid to support the chair but flexible enough to bend. The spikes on the underside are slightly rounded so it stays on the carpet and does not slide around. Would highly recommend!