The Master Step Up Ring 58-77mm is an adapter ring used to mount a lens or accessory with a 77mm thread onto a lens with a 58mm thread. This type of adapter ring helps expand the compatibility and flexibility of a photographer's equipment, allowing them to use accessories with larger filter thread sizes than their lens or camera. Product Features in Detail Master Step Up Ring 58-77mm The Master Step Up Ring 58-77mm a perfect complement to the Master filter line. Master Stepping Rings are precision machined to properly convert the thread size of your filter and/or lens.