This is a plastic kit with NO mullions in the door. This is a plastic door kit. Door is sized to fit the standard 3/8" wall with a 3" x 6 13/16" opening. They can be hinged to swing in or out, from left or right, and are easily modified to use as interior doors. Kit includes the following: Real brass hinges, brass plated door knobs, brass plated escutcheon plates, clear glazing with interior and exterior glazing.