You probably saw some baseball players wearing this necklace and are curious. Does it work as advertised? Nah. It looks cool and I enjoy wearing it, but it does nothing for pain or tension or stiffness, etc. I know it's very popular in baseball (I myself work for MLB) but at the same time, baseball players are very superstitious, and considering these come in various colors and can be braided, it's not surprising to see them everywhere. I do like mine a lot, though. I'd recommend tossing it in with your clothes to be washed once in a while, especially if you workout or sweat, or even if you shower with it on -- it really does need to be cleaned thoroughly to remove that built-up sweaty smell. Cheaper here on Amazon than in sporting good stores.