A roller shutter, coiling door, roller door or sectional overhead door is a type of door or window shutter consisting of many horizontal slats (or sometimes bars or web systems) hinged together. The door is raised to open it and lowered to close it. Roller shutters work by rolling or sliding up and down through tracks; these tracks are also referred to as guide channels. The slats fit into a small box above the door when rolled up (when opening). This small box is typically installed inside the door known as internal face fix. The file contains construction details of rolling shutter.