Rain-X Original Glass Treatment is a liquid, silicone-based product designed for exterior protection of automotive glass, including windshields, side and rear windows, side-view mirrors, and glass-type fog and headlights. It dramatically improves wet weather visibility by repelling rain, sleet, and snow on contact, and by reducing the adhesion of frost, ice, salt, mud, and insects. This product is not recommended for use on plastic or perspex.