PolarPro Brass 72-77mm Step-Up Ring The PolarPro 72-77mm Brass Step-Up Ring permits the use of 77mm threaded filters on lenses with 72mm filter threads. It has knurled sides to provide a more textured grip when mounting or removing it from a lens. This step-up ring features brass construction to prevent binding and jamming, and a matte black finish to minimize reflections. A protective hard case is included.