I bought it at Dick's Sporting Goods. I wore it three times for an arthritic problem in my knee. I actually started feeling some relief in the knee although some relief may have been from the jell injections I was receiving at the time.
Upon removing at the end of the day on the third full day, my upper thigh felt like it was on fire and developed a "burn ring" all the way around my leg that blistered and itched horribly. After reading the package, I realized I was allergic to the silicone band on the inside of the upper band. It has taken three weeks to heal and is still visible, but at least not itching anymore. As I still want to see if it helps, I am removing the upper band where the silicone is and will wear again.
If you are allergic, stay away and find something without the silicone. I did not attempt a refund as I have already removed the silicone band. I could not find a place on the website to complain, so I posted this review here. I hope it helps so someone else doesn't get burned, literally!
Bottom Line: No, I would not recommend this to a friend