Lounsweer 4″ x 50′ Aluminum Roll Flashing for Roof and Garden, Prevents Roofing Stains, Roof Strip for Moss and Mildew Prevention (1 Roll). Publisher: Lounsweer. Weatherproof Strength: the aluminum flashing is not easy to bend, deform or expand under the circumstance of wind pressure, temperature and humidity, high strength, easy to use and process.