This is a listing for a step-up ring set (37mm to 25, 28, 30, 30.5, and 34mm) of 5 pieces. This adapter ring allows you to attach your 37mm filter to the front of camera lenses with 25mm, 28mm, 30mm, 30.5mm, and 34mm diameters. In a sense, it can also be called a step-down ring. This is a rather unusual camera accessory. If you are looking for one, please consider it. Individual sales are not possible. We apologize for any inconvenience, but thank you for your understanding. How about it, Nikon, Leica, and Hasselblad fans?