The Z-Finder Pro 2.5x is another one of Zacuto’s Optical Viewfinders that allows DSLR cameras to have the correct form factor for video. It offers 2.5x focusable magnification (3x is available),a 40mm diameter Zacuto optical designed lens, an anti-fog coating protective cover, an eyecup preventing extraneous light leakage, a diopter and a field of view perfectly matched to 3” LCD screens. The diopter allows you to dial in the focus to match your eye. If you need extra focal point you can use the Z-Finder Extender Frames. The Z-Finder Pro 2.5x has a diopter range of -4.75 and up (unlimited with extender frames). These are semi-permanently stackable frames that attach to the skirt of the Z-Finder Pro and extend the Z-Finder glass further way from the LCD screen for people who are farsighted.