Available with and without the integrated protective filter, the Kowa Front Ring provides an 80mm front diameter with 77mm filter threads for use with common motion picture accessories. Front elements for the Kowa Cine Prominar lenses are becoming more and more rare. Protect your lenses with a seamless, useful solution. Installation is done by simply threading the Duclos 80mm Front Ring onto the existing filter thread of the Kowa lens. (product photo shows the 80mm Front Ring with the optional protective filter).