Nikon MC Zoom Eyepiece 13-30x/20-45x/25-56x. All lenses are multilayer coated for maximum brightness of view field. “MC”stands for Multilayer Coating. The turn-slide rubber eyecup is applied to the wide type eyepiece for comfortable viewing. It helps you position your eyes at the correct eyepoint.Optics employ Eco-glass containing no arsenic or lead. This eyepiece gives a 20-45x magnification with 60mm objective scopes and 25-56x magnification with 78 and 82mm objective scopes