Product review (5 stars): It really works!
I have these under my 20+ year old washing machine. Shaking is now history, and I no longer have to worry about bugging my downstairs neighbors (one of many problems with living in a condo).

One thing that may not be clear from the pictures is that the color (blue in this case) is only on the very bottom (most of the feet are still black), so when these are sitting under your washing machine, no one is going to notice it.