The Sensei PRO 49-55mm Aluminum Step-Up Ring permits the use of 55mm threaded filters on lenses with 49mm filter threads. It has large side knurls to provide a more textured grip when mounting or removing it from a lens. This step-up ring features a lightweight aluminum alloy construction with a corrosion-resistant, matte black, hard-anodized finish for durability and to minimize reflections.