Stepping rings, also known as adaptor rings, allow the use of filters and accessories that are slightly larger or smaller in size than the front screw thread of the lens.\n\nStep-Up rings in particular provide a way to fit a larger diameter filter or accessory onto a lens with a smaller thread diameter. The Step-Up ring screws onto the lens's front thread and provides a larger thread which can then be used for attaching other elements, including more Step-Up rings.