Forney 57057 Lens Replacement Plastic, 4-1/2-Inch-by-5-1/4-Inch, Clear, 2-Pack Standard clear plastic replacement lenses High quality material offers superior protection from dust, weld spatter and impact Fits most brand name helmets using 5 1/4 inch x 4 1/2 inch window opening Meets ANSI Z87.1 safety standards