Converts the thread size of your lens to the thread size of any other accessory. Step down ring size: 82-77mm, 77-72mm, 72-67mm, 67-62mm, 62-58mm, 58-55mm, 55-52mm, 52-49mm, 49-37mm. Step up ring size: 37-49mm, 49-52mm, 52-55mm, 55-58mm, 58-62mm, 62-67mm, 67-72mm, 72-77mm, 77-82mm.
