I guess I'm a bit slow. But, I've been noticing that many baseball players have been wearing this necklace around their neck that looks like a noose or a knot. I really didn't think anything of it. Until yesterday (Mother's Day), when many of the players wore pink necklaces (Breast Cancer Awareness). All along, I just thought that it was just a piece of rope jewelry that was trendy amongst the players. Or that it was a tribute of some kind, like the ribbons they wear sometimes.
So, the necklaces are Phiten Titanium Necklace and actually have a purpose. It seems similar to magnetic jewelry. Apparently, it's been around for the past 3 years.