Angle bead ( corner bead )have a smooth round nose bead with diamond mesh wings for the keying of plaster right up to the nose of the bead. On the outside is the finished edge which is where one side of your drywall knife runs on when you are applying drywall mud. The two flanges sit flat on your raw drywall. The diamond decoration along the length of the flange act as a keyway for holding the drywall mud to the drywall and the corner. This mesh insures a perfect bond and provides effective reinforcement where most needed. Straight edge nose is easy to install and permits plumb straight outside corners. Excellent protection for corridor corners exposed to traffic.