In Sicario, Reggie introduces cop Ted (Jon Bernthal) to Kate Macer (Emily Blunt). After having some drink and dancing, they become intimate, and then Ted brings out this band from his pocket. Looking at this band Kate runs for the gun.
How does she figure out just by looking at this band, that Ted has been sent to kill her or to extract info from her about the operation going on against Manuel Diaz?