Made of extrusion plastic. Structure of cover profile. U-shape edge banding,T-shape profile, inward bending, not vertical angle.Very firm, flat and stable.More easy to install,unbreakable in cold weather. Used for covering the slot or rabbet of aluminum profile ,Make a dust cover and sealing the groove of the profile . Protecting profile groove from dust and decorate the profile surface, make perfect look on the surface of profile.