They work very well. The ruby red bottoms seen to be holding up better than most other felt, to our other pads I've tried.
My only issue of that the 'cup' is slightly too large for the diameter of the wooden chair legs I have around my kitchen table. Is I light the chair the cups will fall off. I remedied this by using some clear tire wraps to secure the cups to the chair legs.
Maybe make a few sizes of the cups? Other than that, the rating would be a 5 star rating.