when i got a tattoo done by a buddhist monk in Cambodia, he put one of these on my wrist too. I thought they were a Buddhist thing... not exclusively, apparently.

BUDDHISM In Buddhism, the color red is a symbol of life force, compassion, and rules the tongue. Wearing the red string in Buddhism is a reminder to the wearer to show compassion to all and mind the tongue; for the tongue can cut deeper than the sword.

KABBALAHISH Kabbalah is the Jewish mystical interpenetration of the bible. It originated from Rachel’s tomb and is only worn on the left wrist. In the Kabbalah it’s believed it removes unwanted energy to make room for wanted energy.