My son recommended your product to me with a very strong personal review so I purchased the small and medium devices and tried them on some rib pain that I had after a fall. Put the small (rectangular) device on my lower chest and instantly lost the pain. I wore the device for several hours with no pain. But, unlike I'd read in some online reviews, my pain didn't return when I removed the device. Later that same day, the injured rib started aching in my back so I use the larger (square) device there and, again, no pain. I wore it for several hours as well and, just as with the chest application, no pain after I removed the device....