This type of rollers represents the upgraded version of basic rollers. The roller is enclosed by cassette and it is protected against dust. The cassette has a variety of colors like: white, brown, golden oak color or walnut color. It fits perfectly on the window's frame. Folding the windows is no longer a problem because the blind will be fixed on the glass in any position. For opaque materials, the cassette has an essential role because it reduces the daylight almost completely.