That thing is probably the most cruel torture instrument ever invented. It’s made of foam - F.O.A.M. - yet it hurts like hell. I hate it. It is a very unpleasant kind of pain, when you roll over this thing with your thigh, on each side separately of course. The pain makes me feel angry, ashamed and embarrased. And you know what’s best about it? That it probably was invented by some clever foam producer who was trying to increase its turnover and thought ‘Well, let’s just say it helps with, er, fascial problems or something. Sounds good, get some doctors and therapists as testimonials and here we go’. And still everybody is torturing themselves with this thing (which btw costs about 30 bucks). Including me. As I said, the most cruel torture instrument, because you torture yourself with it, even buy it for good money, and believe that it’ll you do you good.