Supposed to be heavy enough to use with medium pile carpet. With 1/4 inch berber the indentations were so deep I could hardly move my chair and I only weigh 165. Would not recommend this product for use on carpet of any height.
I like the mat very much. It has worked out very well. The only issue is the label that was glued to the top surface was difficult to remove and left discoloration on the area where it was attached.
This mat was delivered the next day after order was placed. It has performed well since that day. The "cleats" are deep enough to keep the mat from sliding. However the wheels of the chair create depressions in the mat which prevent the chair from sliding freely. After the "body" weight is off the chair the depressions go away.
Not much to review. It is as described. Would recommend Staples offering a floor mat made out of carpet material with a non-slip bottom. Would be much better than plastic.