The PolarPro 77-82mm Brass Step-Up Ring permits the use of 82mm threaded filters on lenses with 77mm 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. PolarPro 77-82-SUR Specs Step-Up Size (Lens to Filter) 77 mm to 82 mm Ring Thickness 4.6 mm Ring Material Brass Knurling Side Packaging Info Package Weight 0.28 lb Box Dimensions (LxWxH) 5.45 x 4.6 x 1.3"