In Germany and other parts of Europe, rolling exterior shutters on tracks (de) have become ubiquitous, although they lack the decorative value of traditional shutters. When open, these type shutters roll up into boxes concealed in the thickness of the wall above the window. They are typically raised and lowered manually, such as by a rolling pull made of flat nylon cord, but they can be equipped with electric operating mechanisms. These shutters allow some light in the room when not fully lowered, but wholly block light when completely closed. Variations include frame extensions that allow the closed shutter to swing out like an awning or Bermuda shutter.