Four leaf clover ring. Just add three friends who also have one.
If you saw last season's episode of It's Always Sunny in Philadelphia, then you'll know exactly what this is is a replica of. In the episode 'The Gang Gets a New Member' you see the four guys put their pinkies together, each sporting a ring, which makes up 1/4 of a four leaf clover. Show your Philly love with pride!
It is meant to be a pinky ring, so keep that in mind. Order 4 for your gang!