Product review (4 stars): Washing machine still shakes, but it does prevent that shaking from being transferred to the floor below
Does the washing machine still shake?  Absolutely.  These do not stop the washing machine from shaking.  It does seem to limit the transfer of that shake to the ground below, therefore reducing the shaking of the floor and walls surrounding the washing machine.  I will say, to be prepared for a difficult installation though.  Our washing machine, like many others, is crammed between a dryer and a cabinet, which made it quite an exercise to get these in place.  And once we did think they were placed properly, the machine shook more violently than ever.  It turned out that one of the washer legs was sitting on the edge of the pad which is raised slightly from the middle of the pad.  Once we fixed this, it worked fine.