The instructions say not to use it on thick carpet with a pad. However I couldn't find anything that would work better so this is what I bought. So far it is working fine. It does get indents but they come out after I leave my chair.
This pad would probably work fine on 1/4" carpet with no padding but consider a heavier weight mat for any thicker or padded carpet. Chair wheels tend to dent the mat when used on thicker or padded carpet.
Not nearly as thick rugged and durable as the one I purchased from another vendor for the same price. I'm sure I'll have to replace this at some point in the future as a result.