It's the crest that they all wear to show that they are part of the family.
Alice:Ribbon necklace
Rosalie:Necklace
Esme:Bracelet
Carlisle:Ring
Edward, Emmett and Jasper: Wrist braces.
Hope this helps!!
It was something added in the movie. It's a crest that has a symbol with a hand, a lion, 3 clovers, and an arrow. We don't know exactly what those things represent. But the objective wass to sort of bond the cullen family together.
The Cullen crest relates to perpetuity and danger and courage. Costume designer, Wendy Chuck had the idea of a family crest , and produced drawings which prop master, Cynthia Nibler took to completion. Each family member wears the crest in a distinctive, personal way. Rosalie wore her crest as a piece of jewlery on a chain; Alice had a small crest on a ribbon she wore around her neck; Edward, Jasper and Emmet had their crest on a leather band that could be worn like a wrist guard; While Dr. Carile Cullen had his set in a ring.
