Roller shutters are a type of shutters that are composed of several horizontal slats, usually made of steel or aluminium, and hinged together. They are generally used on doors and windows. There are different types of roller shutters, depending on how the shutters were installed in the doors. For instance, they could be built-on if they are mounted on the exterior of the door. integrated if the door and the shutters are built as a single unit, or built-in if the shutters are installed below the door's lintel.