Anti-Possession Symbol
From Super-wiki
Following Sam's possession by Meg in 2.14 Born Under a Bad Sign, Bobby gives Sam and Dean each a Charm Amulet which features a symbol which will stop demonic possession.
In 3.12 Jus in Bello, the boys reveal that they have had these symbols tattooed on their chests - as have many Supernatural fans!
- see also Tattoos and Fan Tattoos
