5/8″ X 5/8″ corner brace.
3-1/2″ X 3/4″ X 3/4″ corner brace. Screw in place using #8 panhead screws ( not supplied )
2-3/4″ X 3/4″ X 3/4″ corner brace. Staple in place.
2″ X 3/4″ X 3/4″ corner brace.