Does the job for the most part as long as you don't need to move too far out of place. Even though the dimensions are listed the total area in practice is too small and makes it difficult if you have to veer away anywhere other than from directly in the installed location but that would explain the special economy pricing.
This is a plastic mat to protect the living room carpet and help the chair roll more smoothly. To me the key was price which at [$] could simply not be beat.
I used this product on a wooden floor so the cleats created an uneven rolling surface. But the floor underneath is protected so that's good. And considering the low price I really can't complain aside from the glue-like smell from the mat on the ride home...