As the other reviews mention, the foam used in this isn't all that supportive, but it still adds a moderate amount of comfort to existing stools.On an existing shop stool with a thin (1") foam cushion, this let me sit on a stool for 2-3 hours instead of 1 hour before my butt hurts.I think adding to the foam cushion as other reviews say would make it a lot better, but this does of course add to the total cost.Otherwise, the cover is very well made, looks great, fits well and seems reasonably robuSee full review