Does not hold its shape. Material not strong enough to allow a standard task chair to roll smoothly because any weight will cause the mat to leave indention marks from the chair rollers. This will be going back to the store.
I bought this to replace a mat that was beginning to crack after approximately five years of use. This man is softer than others I have had which is actually a good thing. It took less than four hours for the mat to settle down and become flat after I put it on my carpet. Although the rollers of my home office desk chair make indentations in the mat because the mat is softer these are very easy to roll out of. My previous mat was stiffer and I actually had to lift the chair out of the indentations to move it. Based on the two weeks I have used it I would buy this mat again.
It works fine. On medium pile carpet it prevents the chair from ripping or destroying the carpet but still leaves pretty serious indentions from the wheels.