as some reviews noted it is a bit soft however that doesn't keep it from doing its intended purpose giving your work chair with wheels a better surface to roll and to keep your carpet in good shape. Pleased with it so far.
it really struggles at the top end of medium pile carpets. Slides around a lot which isn't too bad to deal with just need to recenter it every few days but the plastic itself is pretty thin resulting in the chair easily making deep divots that you cant roll out of easily and that suck the wheels back in so small location adjustments are difficult