Curtains of external protection It is aluminum or zinconum curtain of slat sliding up and down (vertical movement) mounted outside the window. It moves either manually or with an electric motor and can be supplied with remote control they are made of aluminum or galvanized iron or plastic PVC but the most common is made of aluminum. Benefits of rolling shutter. Thermal insulator Insulator for dust Insulator for rain Soundproof Insulator for light, sun and ultraviolet rays Protection against intrusion and theft.