Update: After a month of use.
I purchased one used for a good price, so I did not give a crap if it worked in a positive way or not. Well, I put it on my amp where my 2 power transformers are. Played a disc that sounded great before and played it again with the stone on it. The results were easy to hear, darker background, more detail along with more body and weight, took it off and the loss of image tightness and depth and less and all the above was diminished. In the past, I’ve tried brass weights, etc., and even just books to add damping and none ever stayed. So, this stone is doing more than damping by its weight which is not that much. I don’t change my gear like socks, so I am very familiar with how it sounds, this stone was a surprise that is staying on top of my amp. It does what it claims it does. Best $90.00 I spent in a long while.