My carpet is only 1/4” with an 8lb pad. I only weight 170 and the mat has depressions each day where the chair wheels were. Not very good performance for a mat that supposed to be for a medium pile up to 3/4”. Not sure it’s going to last very long.
I measured my carpet as directed and chose the low-pile based on that. This mat is too soft for my carpet and the wheels on my desk chair sink in creating divots that it's hard to wheel out of. I stopped using it after a week and it's now sitting on my cellar's cement floor.