The NiSi Brass Pro 52-77mm Step Up Ring allows the use of 77mm threaded filters on lenses with 52mm standard filter threads. Featuring a durable brass frame with Knurled sides for easier grip. The Brass Step up ring prevents binding and jamming making it easier to remove compared to standard aluminium setup rings.The NiSi Brass Pro Step Up Ring has a special anti-reflective felt treatment on the inside of the frame to minimise reflections and features a matte black finish. The anti-reflective felt treatment make them the perfect companion for long exposures..