24'x100' 5.5mil Panda FilmThe black and white Panda film is highly efficient, and both sides have a purpose the white side can disperse the light by 90%, whereas the black film prevents the light from penetrating. The heavy duty film is waterproof so, don't worry about algae and mold growing on the walls; with the Panda film, the efficiency of the horticulture lights in no time. Waterproof Filming: The heavy duty film is highly waterproof, so it does not allow algae and mold